CURT 42225 1-7/8, 2 and 2-5/16-Inch Chrome Steel Switch Ball Set, Up to 8,000 lbs. GTW. Fits 1-7/8" (3,500 lbs. GTW), 2" (6,000 lbs. GTW) or 2-5/16" (8,000 lbs. GTW) couplers (independently tested in accordance with SAE J684 for safety andproven safe). 1-1/8" neck diameter, 1" shank diameter, 3/4" rise and 2-1/4" shank length. Shank bears the weight, freeing the coupler from friction and binding, and exclusive 'J' groove design ensures a secure system (U.S. patent# 5,169,168; Canadian patent# 1,325,445) No tools, coins or pins required for trailer ball installation (zinc-plated hex nut and helical lock washer for mounting the shank). Constructed from high-strength steel and protected by a premium grade, nickel chrome-plated finish.