These end caps are for use on all sizes of Bauer series 310, 311, 313, 314, 321, and 322 extension ladders, series 330 and 331 straight ladders 8′ – 16′ lengths and model 31516, 31520, 31524, 31528, and 31532. The kit includes 2 black plastic end caps and all hardware necessary for installation. These parts maintain the original duty rating of the ladder. .