Size: 20mm. Used for 20mm vial and 20mm vial crimper.
Half tear type: This cap is falf tear type, that means when you tear off the plastic cap of it, the aluminum cap can't be teared off. Please see the picture.
The cap is not sterile, but can be sterilized by high temperature.
Description
20mm Black Flip Top Caps-100 Pcs Aluminum-Plastic Black Caps for Glass Vial