White grooved screw cap, self-sealing DIN 18 ring for bottle.

The "self-sealing" side, which does not require a seal, allows multiple uses because there is no possible reaction with the product contained.
 
In addition, thanks to its DIN18 seal, the cap, made of polypropylene, is tamper evident. This attests that the bottle has not been opened between the moment it was packaged and the moment the user opens it.  

Size: 20.4 - Ø 21.7
Material: Polypropylene