78-44 Traveler adapter works with Schaefer 8 series blocks and Schaefer six- wheel traveler cars. (72-92, 72-78, 72-76) Remove the two fasteners and swivel at the bottom of your 8 series blocks and re-attach to the 78-44. SS Spring supports block on traveler car for secure and safe usage. L=1-1/4” (32mm), W=1-5/32” (29mm), H=2-11/16” (68mm), Weight=4 oz. (113g)