1pk +grease compatible with Intex Small Top Cover O-Ring Model 10325, approx 5" ID

Use silicone grease to delay o-ring rot. Works on these pumps 56637 (Krystal Klear Model 637--older smaller version) 56635 (Krystal Klear Model 635) 58631 (Krystal Klear Model 12 and 12R) 58603 (Krystal Klear Model 02 and 603--older, smaller version) *CAUTION* The newer models for this 530 GPH pump uses a different o-ring, Part number 13413 with an id approximately of 4.5". Be sure to measure your old o-ring or the center of the groove it sits in. Order 13413 for the modern larger models 530 GPH (603/25FP603) and the bigger modern model 1000 GPH (637).