Raceworks Thread Identification Kit Description: There are 3 different kits available, please choose the correct kit in the drop down menu. AN / Imperial Contains both male and female thread identifiers in the following sizes3/8″ -203/8″ -24 (AN-3)7/16″ -20 (AN-4)7/16″ -241/2″ -209/16″ -18 (AN-6)9/16″ -243/4″ -16 (AN-8)7/8″ -14 (AN-10)1-1/16″ -12 (AN-12)1-5/16″ -12 (AN-16)1-5/8″ -12 (AN-20 BSP/NPT Contains both male and female thread identifiers in the following sizes1/8″ BSPT1/4″ BSPT3/8″ BSPT1/2″ BSPT3/4″ BSPT1/16″ NPT1/8″ NPT1/4″ NPT3/8″ NPT1/2″ NPT3/4″ NPT1″ NPT Metric Contains both male and female thread identifiers in the following sizes M8 x 1.0M8 x 1.25M10 x 1.0M10 x 1.25M10 x 1.5M12 x 1.0M12 x 1.25M12 x 1.5M14 x 1.25M14 x 1.5M16 x 1.5M18 x 1.5