VialLock cap fit guide

Choose the cap that fits your vial setup.

Start with the outside diameter of the vial top. Small VialLock caps are the 14mm fit used with VialLock 3mL cases. Large VialLock caps are the 20mm fit used with VialLock 10mL cases and the other large-fit vial sizes listed on the cap product page.

Choose cap color, fit & pack Compare all cases

Storage accessory only. VialLock caps are reusable protective covers; they are not sterile seals and are not medical devices.

VialLock flexible TPU vial caps in available colors
Flexible TPU caps · available options come directly from Shopify

Small cap fit

14mm / 0.55 in

Choose Small for standard 3mL vial tops and VialLock 3mL case families.

  • Pairs with VialLock 3mL cases
  • Measure the outside of the vial top—not the vial body
  • Select the live color and pack options on the product page
Shop compatible 3mL cases

Large cap fit

20mm / 0.78 in

Choose Large for VialLock 10mL cases and compatible 5mL, 10mL, 20mL, or 30mL vial tops that measure 20mm across.

  • Pairs with VialLock 10mL cases
  • Verify the vial-top diameter before ordering
  • Select the live color and pack options on the product page
Shop compatible 10mL cases

Measure before ordering

Measure the vial top in three quick steps.

  1. 01Measure across the top

    Use the widest outside edge of the vial neck or crimp top.

  2. 02Match the diameter

    Choose Small for 14mm or Large for 20mm.

  3. 03Choose live options

    Pick an available color, fit, and pack on the cap product page.

Cap questions, answered

Know before you choose.

Which cap fits VialLock 3mL cases?

Choose the Small cap fit. It is designed for standard 3mL vial tops that measure 14mm / 0.55 in across.

Which cap fits VialLock 10mL cases?

Choose the Large cap fit. It is designed for 20mm / 0.78 in vial tops used with VialLock 10mL cases.

Are the caps included with a case?

Caps are optional accessories unless the product page or cart explicitly shows them as a separate selected item.

Are VialLock TPU caps sterile?

No. They are reusable storage and organization accessories, not sterile seals and not medical devices.

How should the caps be cleaned?

Hand wash with mild soap and warm water, then allow them to air dry before reuse. Do not boil or autoclave.

Which colors and pack sizes are available?

The cap product page shows the current Shopify options. Unavailable combinations are disabled automatically.