• For use with 1500 GPH filter pumps and lower
• ID measures approximately 5"--does NOT fit the newer models.
• Includes 4 o-rings
• Replaces the O-Ring on the lid of the pump
• Fits 56637 (Krystal Klear Model 637--older smaller model) 56635 (Krystal Klear Model 635)
• Fits 58631 (Krystal Klear Model 12 and 12R) 58603 (Krystal Klear Model 02 and 603/26603--older smaller model)
• *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)

1 to replace and 3 for spares