78-48 Traveler adapter works with Schaefer 8 series blocks and Schaefer four- wheel traveler cars. (72-80, 72-83) 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=2-9/16” (65mm), Weight=4 oz. (113g)