Crown KK100 Universal Residential And Light Commercial Oil Burner Coupling Includes: The Koupling King II universal oil burner coupling comes assembled with a 1/2? motor shaft end, and a 5/16? fuel unit shaft cap on the other. A 7/16? fuel unit shaft end cap is also enclosed. Over-all 5? assembled coupler length. Cut To Length Design. Just Use A Hacksaw To Cut To Your Desired Length. Replaces Westwood S85-500, #88