This is a well made reproduction of a German WWII flared type rubber eye cup for the ZF4 scope. Yes naturally this piece is made from a good quality rubber as the original. The opening diameter is 30 mm. It is only $5.50 to ship this liner anywhere in the US, Canada, Australia, NZ and most of Asia. Postage within the EU is $5.00, all others pay actual postage. Naturally I do offer the possibility of combining postage to save you money. I take PAYPAL and other payment options are also available, just ask and I will see what I can do.