IPD Gage Carbide Ball Contact Point Set Covers UN Series 24 to 3 pitch single and multiple starts Set includes 7 pairs of Ball Contact Points... 1/32" 3/64" 1/16" 5/64" 3/32" 7/64" 1/8" All contact points 1/4" in length, 4-48 thread. Works with IPD Gage # 30-640-7.