20BORE-20MJ STRAIGHT

The B1 end is a bore type connection with a 1-1/4 inch tube OD and a drill diameter of 1.256 mm. That end accepts a tube directly rather than threading into a port. The B2 end is a 1 5/8-12 Male JIC fitting with a 37-degree flare, built to SAE J514 spec. So you've got a bore connection on one side and a standard JIC male on the other, which is a pretty common pairing when you're transitioning between tube and flared fittings in a hydraulic line.