JACKEL Sump Pump Check Valve, Clear, Model: DJ-545C

Amazon.com Price: $19.99 (as of 20/09/2023 10:16 PST- Details)

Fits 1-1/4″ or 1-1/2″ black, galvanized or DWV Schedule 40 pipe
The most durable flapper in the industry
Strong and durable CLEAR ABS body