A Corker There's a tool for everything. Think post-hole diggers for a model railroad layout. All right, all right. Think cork borers for all those solid corks and rubber stoppers in laboratories, the ones that need holes for glass and rubber tubing. Our each is a set of (3) 3-3/4" long brass tubes with sharpened ends and red-plastic T-handles. Diameters are 9/32", 7/32" and 5/32". They're nested on the 4-3/4" pin used to clear the plug from the tube.