this unique black alloy one piece 1" / 30mm stubby scope ring set is specially made for compact scopes. 4 ring screws per ring giving 4 points of secure contact, built in anticant. fits 30mm scope tube and 1" scope tube with provided spacers. 36mm base to centre. 36mm between rings. 87mm overall length. + I have 222 Loctite listed and its recommended to use on the screws.