The 1598 U-adaptor allows blocks with up to 15 mm (19/32") posts to be attached to swivel bases or to other blocks with 15 mm (19/32") posts.   Weight (g) 44.4 g Weight (oz) 1.57 oz Shackle pin Ø (mm) 8 mm Shackle pin Ø (in) 5/16 in Maximum working load (kg) 816 kg Maximum working load (lb) 1800 lb Breaking load (kg) 1633 kg Breaking load (lb) 3600 lb A (mm) 12 mm A (in) 1/2 in B (mm) 22 mm B (in) 7/8 in