3-Way Y Block Adaptor (MB-Z3-2) with 1 x 9/16" female (in) and 3 x 3/8" female (out)
This adaptor is made with a threaded hole for a mounting screw. Typically, adaptors are required to connect to 1st stage or regulator hoses
This enables at 1st stage a 3/8" port to be split/extended into 3 ports