* Note: Terms such as Ben Wa balls, Geisha balls, vaginal balls or pelvic floor training balls all refer to the same principle: a solid inner ball rotates within a hollow outer ball and creates stimulation through vibration when you move.

This guide is based on my decades of experience as a midwife and pelvic floor therapist. You will learn how true Kegel balls* work, which designs exist, which sizes/weights make sense, how to recognise quality, and which materials are genuinely body-safe. You will also find certified medical Kegel balls (Viball®) for women, men and couples – including everyday use, targeted training, and partnered sex.

What are Kegel balls* and how do they work?

In the original sense, a Kegel ball* consists of a hollow outer sphere with a freely rolling inner sphere. When you move, the inner ball rolls and produces vibration that stimulates nerves and activates the pelvic floor muscles — vaginally or rectally. The more movement, the stronger the effect. Electrically vibrating products are vibrators and do not replicate this mechanical effect.

Efficiency depends on the dimensions: if the inner ball is too large (too little play) or too small (too little mass), vibration is weak. Thick outer shells, threads, eyelets or screws reduce inner space and slow the inner ball — again reducing vibration. Single balls are usually more efficient than rigid double-balls, which rarely oscillate in sync.

Small Kegel balls

Small balls are best for short, active exercises. For long everyday wear they are often unsuitable because you tend to “hold” them – encouraging unnecessary baseline tension up to hypertonicity. Physically, larger balls generate stronger, more perceivable vibration during movement.

Recommendation: For daily wear choose the largest comfortable size. It will rest above the vaginal opening without the need for constant “holding”.

Large Kegel balls*

Large balls are ideal for everyday life and sport: they sit more securely without ongoing increased muscle tone and produce stronger vibration. Many also enjoy the fuller sensation erotically.

Construction note: With some metal balls, thick shells, threads or inward eyelets reduce inner space and limit the inner ball’s roll — vibration suffers. Efficient balls feature a thin-walled outer shell and optimised inner/outer ball dimensions.

Selection of Kegel balls by size

Diameter (mm)	Brand	Model	Material
28	Satisfyer	Balls C02 Single	Silicone
28	Luvsex	Kegel balls	Silicone
29	Lelo	Luna Beads Mini	ABS, Silicone
31	Magic Shiver	Kegel balls	Silicone, PU
32	Satisfyer	Balls C03 Double	Silicone
34	Mshop	Kegel balls	Silicone
34	Satisfyer	V Balls	Silicone
35	Lelo	Luna Beads	ABS, Silicone
35	BEQOOL	Kegel balls	Silicone
35	Amorado	Pink Kegel balls	Silicone
36	Fun Factory	Smartballs Duo	Silicone
36	Je Joue	Ami Kegel Balls	Silicone
36	Theros®	Viball® 36	Implant-grade steel AISI 316L
36	Sweet Smile	Kegel Training Balls	Silicone
40	Theros®	Viball® 40	Implant-grade steel AISI 316L
45	Theros®	Viball® 45	Implant-grade steel AISI 316L
45	Sweet Smile	XXL Balls	Silicone
50	Theros®	Viball® 50	Implant-grade steel AISI 316L
55	Theros®	Viball® 55	Implant-grade steel AISI 316L
60	Theros®	Viball® 60	Implant-grade steel AISI 316L

Heavy Kegel balls*

“Heavy” is often sought to intensify training. As a pelvic floor therapist I recommend: use weights/cones only short-term for active exercises, not for hours in everyday life. For daily wear prioritise maximum suitable size rather than maximum weight — relaxed, secure and effective.

Selection by weight

Diameter (mm)	Weight (g)	Brand	Model	Material
28	103	Luvsex	Kegel balls	Silicone
34	80	Satisfyer	V Balls	Silicone
34	109	Satisfyer	V Balls	Silicone
34	149	Satisfyer	V Balls	Silicone
36	130	Sweet Smile	Kegel Training Balls	Silicone
36	140	Theros®	Viball® 36	Implant-grade steel AISI 316L

Extra heavy: Theros® Massive Balls – see below.

Alternatives to Kegel balls*: Hollow or solid balls

Hollow XXL balls and solid balls do not contain an inner ball and therefore do not create mechanical vibration. They are used for specific goals: maximum fullness (hollow) or high weight/pressure/mass (solid) — e.g. for short, intense drills, rectal use, or extra contact during sex. Always check precise material specifications (see Materials).

Hollow balls (XXL)

They provide fullness rather than vibration. New: Viball® offers true vibrating XXL Kegel balls (36–60 mm) made of implant-grade steel — as certified medical devices.

Solid balls (extra heavy)

They work via weight/pressure/mass. Not for prolonged vaginal wear, but ideal for short, intensive strength work, for anal use, and during sex (more contact/G-spot stimulation). Example:

Theros® Massive Balls – sizes & weights

Diameter (mm)	Weight (g)	Brand	Model	Material
36	190	Theros®	MB36	Implant-grade steel
40	270	Theros®	MB40	Implant-grade steel
45	380	Theros®	MB45	Implant-grade steel
50	520	Theros®	MB50	Implant-grade steel

Kegel balls* made of silicone, metal or stainless steel?

“Medical silicone” is not a protected legal term. Compositions (plasticisers, adhesives, coatings) vary, and with long wear some products may release substances. For metal products without exact alloy designation (“stainless steel” without a standard), allergies and coating fakes are a risk.

Implant-grade steel AISI 316L is biocompatible, anti-allergenic, smooth, durably hygienic (disinfectable/sterilisable), odour- and stain-resistant and fully recyclable. Steel also transmits vibration far better than silicone. Bottom line: For vibration efficiency, health, hygiene, longevity and sustainability, implant-grade steel is the best choice.

How to use Kegel balls*

Insert gently with a little lubricant. Effect depends on movement – best are pendular/circular activities (walking, dancing, cycling). Avoid jumping/stomping, especially with a weak pelvic floor. Do not wear while sleeping; avoid long internal wear with plastic/silicone products.

What movement works best?

Circular/pendular pelvic movements — e.g. brisk walking, cycling, dancing (belly dance is ideal) — create the strongest vibration.

Which factors determine quality?

1. Fit

More sizes = better fit and secure hold without “clenching”.

2. Weight range

Like strength training: progressive loading enables measurable gains.

3. Vibration energy

A thin-walled hollow ball plus correctly dimensioned inner ball produces maximal vibration.

4. Material

Transparent specs (e.g. AISI 316L), biocompatible, seamless, disinfectable/sterilisable.

Which Kegel balls* for which application?

Quick overview: Active use = short, targeted pelvic floor exercises focusing on strength and muscle control (like using dumbbells). You may choose smaller/heavier balls — but only for limited time. Passive use = relaxed use in daily life/sport for steady, movement-dependent vibration and erotic stimulation. Choose the largest comfortable size that sits securely without holding.

Active pelvic floor workout (short-term)

Smaller/heavier balls for short, focused drills. Do not wear for extended periods.

Everyday life, sport & pleasure (long-term)

Larger balls for secure hold, stronger vibration and relaxed, sustainable use — no “clenching”.

Which Kegel balls* are right for me?

Marketing claims are not evidence. Only certified medical devices must prove safety and efficacy. Terms like “medical” without certification are meaningless.

Viball® – medical Kegel balls* for women, men and couples

Viball® combines the key quality criteria: highest efficiency through optimised physics, implant-grade steel AISI 316L, six sizes, nine weights, fully without string for invisible wear, and certified as a medical device. Ideal rectally (including prostate stimulation), as a “contact enhancer” during sex, and for passive everyday stimulation.

Viball® – all sizes at a glance

Why they help after pregnancy

During daily use, occasional vibrations increase pelvic floor awareness, promote contractions and thus support recovery and continence — pleasantly aided by arousal, which boosts motivation to keep training.

Key questions & answers

What are Kegel balls*?
True Kegel balls = hollow outer ball + freely rolling inner ball → vibration through movement.

Why do some barely work?
Poor dimensions or inner obstructions slow the inner ball — weak vibration.

Which size is right?
The largest comfortable size — it rests securely above the vaginal opening without holding. Viball® offers six sizes.

Which material is best?
Implant-grade steel AISI 316L — biocompatible, anti-allergenic, smooth, hygienic, durable; transmits vibration best.

How long can I wear them?
Daily use: as long as you like (with suitable size/material). Training weights: short-term only.

* Note: Terms such as Ben Wa balls, Geisha balls, vaginal balls or pelvic floor training balls all refer to the same principle: a solid inner ball rotates within a hollow outer ball and creates stimulation through vibration when you move.

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