U-adaptor allows blocks with 3/8 in (10 mm) posts to be attached to swivel bases or to other blocks with 3/8 in (10 mm) posts.
Shackle pin dia. (in) 3/16
Weight (oz) .48
A (in) 1/2
B (in) 7/16
SWL (lb) 1250
Breaking strength (lb) 2500.