This part fits on 7" Steel, 8" Steel, 9" steel or 8" Resin frames. This is a replacement style of joint which utilizes a 1 inch rail (or track). It measures 5" 5/8" wide, 3" 3/4" deep and 3/4" tall. If your pool used part 2173, this part will fit in it's place. You will need to use different screws to hold it in place since it does not use the machine threads that were used by the 2173.
THIS PART ONLY WORKS WITH 1" RAILS. If you buy this part, do NOT purchase 5/8" rails. If you are not certain, measure the rails on your pool. If they are 7/8", they are considered 1" rails.
This is an upper joint, so it should not be used along the bottom of the pool wall.