This is a short stub KF-50 to 2.00 inch MALE G BSPP. This thread size is primarily used in Europe and Great Britain. This adapter converts "G" BSPP thread to a KF 50 flange which is more commonly used in the universal world wide vacuum market.

BSPP = British Standard Pipe Parallel (straight thread) and is often noted G, for example, G(1-1/4).

Adapter KF-50 Flange to 2.00 inch Male G BSPP Thread (British Standard Pipe Parallel), Stainless Steel
Common Dimensions:
A = 2-15/16 inch (75mm)
B = 2-3/8 inch (60mm)
C = 2 inch (51mm)
D = 1-3/8 inch (35mm)