HHIP bund hole spotter features fast and easy way to locate opposite centers. When holes do not extend through material(such as holes for dowel pins, perforating punches, etc.) Blind-hole spotters get the job done simply. Correct size spotter can be used in threaded, drilled or reamed holes. Set includes: 1/8 to 21/32" by 32nds, 6 piece each.