Intex Small Top Cover O-Ring Model 10325 For use with 1500 GPH filter pumps and lower Replaces the O-Ring on the lid of the pump Includes 1 O-Ring Works on these pumps: Intex 56637 (Krystal Klear Model 637) Intex 56635 (Krystal Klear Model 635) Intex 58631 (Krystal Klear Model 12 and 12R) Intex 58603 (Krystal Klear Model 02 and 603)