Features 3/8-16 stainless threaded rod which helps prevent weld spatter from sticking.Also comes quick knobs, 1/4 turn on, 1/4 turn off This is for one set of 1 1/2" Alum. two hole flange pins shown. They are made of 6061 aluminum They will work on hole size 3/8" to 1 7/16" up to 1 1/2" thick flange They have 3/8-16 stainless threads and 45 degree taper Has Quick knobs. Made in USA