This is a Pentair  801428 mechanical seal. They are a direct aftermarket replacement for the OEM version and suits all Onga-Pentair standard pumps as listed below.

This seal fits the following pump sizes:

• LTP1100

• Silentflo-550
• Silentflo-750
• Silentflo-1100
• Silentflo-1500

• Max-E-Pro730
• Max-E-Pro930
• Max-E-Pro1100

• EnviroMax 1100
• EnviroMax 800
• EnviroMax 1500