Pentair R172214 Lock Ring Replacement Pool/Spa Filter, Feeder and Leaf Traps;

This lock ring is designed to use with Pentair Dynamic series I, II RTL/RCF, III RTL/RCF and V inline pool/spa cartridge filter models RDC-25, RDC-25S, RDC-50, RDC-50S, DSC 75, DSC 100 and also compatible with Pentair pool and spa leaf trap models 179, 179-HDB, 179-C, 179C HDB. Also fits Pentair Rainbow high capacity automatic chlorine/bromine pool and spa feeder models HC-3315, HC-3330, HC-3340 and Pentair Predator II mini-cellular media cartridge filters. Measures 7 19/50-inch length by 1 21/50-inch height by 7-3/20-inch width.