Here’s the information for the part with GAP No. 903121:
Product Specification:
This part is specified with a brake stroke of 44, a push rod length of 130mm, and a push rod thread of 1/2 – 20 UNF. The inlet thread is 3/8″ – NPTF, and it has a port angle of 90° and a clamp angle of 45°. The color of the part is specified as Black, and the type number is T12.