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Use the product photo and available options below to choose the case or accessory that fits your setup.
Two cap-fit families
Choose small 14mm, large 20mm, or a mixed pack below.
3mL + 5–30mL · Flexible TPU caps
Flexible Vial Caps
A simple way to color-code and cover compatible vial tops.
What you’re getting
Flexible caps for color-coding and covering compatible vial tops. Choose small 14mm, large 20mm, or a mixed pack below.
Read the full product description
$11.99
Price
Vial fits
3mL + 5–30mL
Cap sizes
14mm + 20mm
Choose an available color, fit, or pack option below before adding to your bag.
✓
Free shipping over $35See progress in your bag
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30-Day Case Fit GuaranteeSupport if the fit is not right
Product description
Everything to know
before you choose.
Flexible TPU Vial Caps | 3mL 5mL 10mL 20mL 30mL | Reusable Protective Caps for Glass Vials
Capacity:
- Small — fits 3mL vials (14mm neck / 0.55")
- Large — fits 5mL, 10mL, 20mL & 30mL vials (20mm neck / 0.78")
VialLock Flexible Vial Caps — REUSABLE & SECURE
Made for every vial size you actually use. Whether you're capping a 3mL peptide vial, a 10mL TRT vial, a 20mL bacteriostatic water vial, or a 30mL research vial — VialLock TPU caps snap on clean, stay put, and protect what's inside.
Soft, flexible TPU grips securely over the vial top without tearing or slipping. Peel off effortlessly when you need access. Reusable, fridge and freezer safe, and easy to clean between uses.
Key Features:
- ✅ Premium TPU — flexible, durable, and tear-resistant
- 🔒 Snug secure fit — works on 3mL, 5mL, 10mL, 20mL & 30mL vials
- 🛡 Protects against dust, dirt, and handling exposure
- ❄️ Fridge and freezer safe
- ♻️ Reusable — hand wash and reapply
- 🎨 Available in 7 colors + Mix assortment packs
- ✈️ Lightweight and travel-ready
Size Guide:
- Small (14mm) — fits standard 3mL vials. Verify your vial's neck OD before ordering.
- Large (20mm) — fits standard 5mL, 10mL, 20mL, and 30mL vials including most research-grade multi-dose vials.
Select your size based on your vial's neck opening diameter. When in doubt, measure the outer diameter of the vial top before ordering.
Compatible With: GLP-1, peptide, TRT, insulin, and research vials with standard neck openings — including 3mL, 5mL, 10mL, 20mL, and 30mL sizes.
Care Instructions: Hand wash with mild soap and warm water. Allow to air dry before reuse. Do not boil or autoclave.
3D Printed Product Notice: VialLock caps are produced in small batches. Minor surface texture variation is normal and does not affect fit or performance.
VialLock caps are designed for storage and organizational use only. They are not a sterile seal and are not intended for medical or clinical use.
👉 Perfect for capping 3mL peptide vials, 10mL TRT vials, 20mL or 30mL research vials — keep every vial protected between uses.
2 fit families
14mm and 20mm
Small 14mm + large 20mm
Small, large, and mixed packs
4.95 / 5176 Judge.me reviews
30 daysCase Fit Guarantee
Fit guidance
Know the fit
before you buy.
Use the vial size, capacity, and cap compatibility below alongside the full product description above.
3mL + 5–30mL
Small and large caps are separated by the vial-top measurements shown here.
14 + 20mm
Choose small, large, or mixed packs according to your vial size.
Complete your case
Use caps to color-code and cover compatible vial tops.
Verified customer reviews
Why customers
choose VialLock.
Rated 4.95 out of 5 across 176 Judge.me reviews.
“It’s perfect and just what I was looking for!”
Verified customerJuly 13, 2026
“With the assorted colors, I was able to color code...”
Verified customerJuly 9, 2026
“Received quickly. Exactly as pictured. Beautifully crafted case!”
Verified customerJune 28, 2026
Questions answered
Choose with confidence.
Which cap size do I need?
Choose small 14mm caps for VialLock 3mL cases, large 20mm caps for VialLock 10mL cases and the other listed large-fit vial sizes, or a mixed pack when you use both.
How do I choose a color and pack size?
Select the color first, then the cap fit and available pack quantity. Unavailable combinations are disabled automatically.
Are cases included?
No. This page is for flexible vial caps only. Compatible VialLock cases are sold separately.
Where are the exact measurements?
Review the complete product description above for fit measurements, care instructions, and compatibility details.
Same fit family
Compare nearby capacities.
3mL + 5–30mL · Flexible TPU capsFlexible Vial Caps