Part Number: 12266738 (Ring, externally threa) Part Number: 12-2667-4 (Ck. valve) Part Number: 12266740 (Ring, external) Part Number: 12266741 (Lens optical eyepiece) Part Number: 12266742 (Lens) Part Number: 12266743 (Lens) Part Number: 12266744 (Lens eyepiece) Part Number: 12266745 (Lens optical) Part Number: 1226674FCT138ATWAX (Ne) Part Number: 12266751 (Retainer) Part Number: 12266754 (Eyepiece) Part Number: 12266755 (Spacer, optical element) Part Number: 12266756 (Spacer) Part Number: 12266757 (Lens)