Originally Posted by
HillRider
Park's web site says the CBW-4 is 1/8" or 3.2 mm thick so that's too thick for the OP's needs. They don't give a thickness for the OBW-4 but the smallest end opening is 10 mm. I have an OBW-1 which is indeed 2 mm thick but the small end is also 10 mm.
timo888 said
about 2mm. The difference between 3.2mm (1/8" or 8/64") and 2mm is 3/64" (5/64"). It depends on the application but that should fit into the "about" category. A millimeter is pretty tiny.