Shaft Vibrating Sheath Size 1 vs Size 2: Which Fits You?
By Cupid's Closet | Published: 2026-11-04
Category: 購入ガイド
Compare Shaft Vibrating Model F Sheath Size 1 and Size 2 using internal and insertable lengths, then decide which vibrating penis sheath fits your body and play style.
Quick answer
Choose Shaft Vibrating Model F Sheath Size 1 if your erect length is roughly 4.2 inches or less and you want a snug, shorter sheath; choose Size 2 if you need about 4.9 inches of internal room or more insertable length. Measure first, because the two sizes differ in internal length and girth.
What actually changes between Size 1 and Size 2
Both sheaths share the same FLEXISKIN real-feel silicone, 8 vibration modes, boost function, and waterproof wireless remote. The meaningful differences are dimensions: Size 1 has a 4.2-inch internal length and a 0.9-inch internal diameter, while Size 2 has a 4.9-inch internal length and a 1.6-inch internal diameter. Size 2 also lists an internal insert length of 0.8 inch, a spec Size 1 does not list.
That means the decision is mostly about how much internal room you need and how much girth the sheath can comfortably accommodate. A longer or thicker erection will feel cramped in Size 1, while a shorter erection may not reach the textured end of Size 2.
The trade-off: snug control versus extra room
Size 1's narrower internal diameter can give a more secure, closer fit for users within its range, which often translates to better control during thrusting. The downside is less tolerance for girth and length; if you are near the upper limit, the fit can become tight or uncomfortable.
Size 2 offers more internal length and a wider internal diameter, which suits users who need room. The trade-off is that a shorter erection may not fill the sheath, reducing sensation at the tip and making the fit feel loose. Neither size is universally better; match the dimensions to your body.
Where the textured sheath buying guide angle matters
If texture and vibration are the main appeal, fit determines whether you feel them. A sheath that is too long can bunch or shift, while one that is too tight can dull vibration transfer. Use the internal length as your primary filter, then consider girth. The catalog does not supply external texture details for these two models, so base your choice on the listed dimensions and the shared vibration features rather than assuming a specific surface pattern.
Decision rules for choosing your Shaft Model F sheath size
- Measure erect length first: Measure from the base to the tip along the top. If you are at or under 4.2 inches, start with Size 1. If you are between 4.2 and 4.9 inches, Size 2 gives you room to reach the end. If you are longer than 4.9 inches, neither sheath covers your full length, so expect the tip to remain exposed. Use internal length, not total length, as your first filter.
- Check girth against internal diameter: Size 1 lists a 0.9-inch internal diameter and Size 2 lists 1.6 inches. If your erect girth feels snug in a 0.9-inch opening, choose Size 2. If you are well under that, Size 1's closer fit may feel more secure. A wider internal diameter is not automatically better; it can feel loose if you are smaller.
- Decide how much insertable length you want: Size 1 offers 6.5 inches insertable and Size 2 offers 6.9 inches. If you want the sheath to add more length during play, Size 2 provides slightly more. If you prefer a compact feel, Size 1 is the shorter choice. Insertable length affects the external feel, while internal length affects your fit.
- Account for the unlisted Size 1 internal insert length: Size 2 lists an internal insert length of 0.8 inch; Size 1 does not list this spec. Do not assume Size 1 has the same value. If that measurement matters to you, treat it as unknown and choose based on the listed internal length and diameter. When a spec is missing, do not guess; use the available dimensions.
Product facts at a glance
- Shaft Vibrating Model F: Sheath Size 1 Black: Internal length 4.2 inches, internal diameter 0.9 inch, insertable length 6.5 inches. This is the shorter, narrower option, so it suits users who want a close fit within those limits.
Shaft Vibrating Model F: Sheath Size 1 Black - Shaft Vibrating Model F: Sheath Size 2 Oak: Internal length 4.9 inches, internal diameter 1.6 inches, insertable length 6.9 inches. This gives more internal room and a wider opening, which helps if Size 1 would be too tight or short.
Shaft Vibrating Model F: Sheath Size 2 Oak
Who each size suits
Best for
- Users with an erect length around 4.2 inches or less who want a snug, shorter vibrating sheath
- Couples who prioritize a close fit and compact feel over extra insertable length
Not for
- Users who need more than 4.2 inches of internal length or a wider internal diameter
- Shoppers who want the longest insertable length in the Model F range
