6 Advanced Practices – Sizing, Fisting and Double Penetration

Introduction: Comparing Advanced Toy Options 📏

Welcome to the sixth part of our Stretching Guide. This chapter looks at size comparisons for more experienced users, including questions about fisting and double penetration. If you are just starting out, visit our beginner's guide first.

Our experience as a silicone toy manufacturer can help you understand a product's dimensions and firmness. A size chart cannot establish your body's limits or guarantee that a particular activity will be suitable.

Size and Shape: What to Compare 🔎

Maximum width: Check the widest part of the model and where it sits along the body. Two toys with the same maximum diameter can have very different profiles.
Neck and base: Compare these separately from the widest section. A narrower neck changes the shape, but it does not establish a suitable wearing duration.
Usable length: Distinguish the insertable section from the total length, which may include the base.
Round or oval: For an oval model, compare both width and thickness. One measurement does not describe the whole cross-section.

Diameter and Circumference: Know the Difference 📐

Diameter is the width across a circle through its centre. Circumference is the distance around it. For a circular cross-section, circumference equals diameter multiplied by pi.

Measurement example: A diameter of 5 cm (approximately 1.97 inches) corresponds to a circumference of approximately 15.7 cm (6.18 inches). This describes a circle, not a recommended toy size.

Adding the circumferences of two objects does not produce a target diameter for using them together. Their combined outline depends on their shapes, positions and deformation.

Common Advanced Sizing Questions 💬

Double Penetration: Comparing Combined Shapes

When comparing a combination of objects, a single diameter cannot describe the complete shape. We do not recommend selecting a preparation toy by adding measurements together. Previous comfort with either object separately does not establish that the combination will be suitable.

Fisting: Why There Is No Universal Target Diameter

A hand has an irregular shape, and its dimensions and joint contours vary. There is no universal toy diameter that establishes readiness for fisting. A familiar measurement on a round silicone toy cannot be treated as an equivalent measurement for a hand.

Silicone Firmness: Why the Comparison Matters ☁️

Very soft Shore 00-30 silicone compresses more readily than firmer Shore A-10. In our experience, this can allow some users to use a toy with a nominal diameter around 0.5 cm (0.20 inches) larger than a comparable shape in Shore A-10.

This is a practical observation, not a fixed sizing rule or a guarantee of comfort or safety. Compare similar shapes and consider the neck and usable length as well as the maximum diameter. If you need help comparing our options, tell us which model and firmness you already use.

Frequently Asked Questions ❓

Can I calculate one equivalent size for two objects?
There is no simple universal conversion. Adding diameters or circumferences does not capture the combined shape or determine suitability.

Does experience with one toy mean another will feel the same?
No. The tip, taper, widest section, neck, usable length and firmness all contribute to the comparison.

Should I automatically add 0.5 cm when choosing 00-30?
No. The difference described above is our practical experience with some users and comparable shapes. It is not an automatic allowance for every model or person.

What can you help me choose?
We can clarify dimensions, explain firmness options and discuss manufacturing possibilities. We cannot determine medical suitability or guarantee a particular fit.

Need Help Comparing Models? 📩

Send us the model names or links and the measurements you want to compare. Please specify centimetres or inches and distinguish diameter, circumference, width, thickness and usable length. Write to us — we are happy to help with product questions.

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Or go back to the full Stretching Guide overview.