Before you buy: checking your vial cap fit
A better cap fit starts with the closure, not the volume printed on the vial. Check these details before choosing a 3mL vial cover.
Measure the existing closure
Measure the outside diameter of the existing vial closure in millimeters. Do not assume every vial labeled 3mL uses the same closure. Keep the original stopper and seal intact.
Compare the exact cap style
Click caps and other covers can use different shapes or attachment methods. Match your closure to the dimensions and photographs of the exact product you plan to order.
Check the case clearance too
An added cover can increase both width and height. If the covered vial will go inside a case, measure it again with the cover fitted and compare it with the case’s allowed dimensions.
If it does not fit
Do not force the cover onto a vial. Contact us with a photo and measurements so we can help identify the mismatch. For direct purchases, request returns within 7 days of delivery; buyer pays return shipping.