This universal-threaded sewer fitting features a standard bayonet end and accommodates six different types of sewer connections with a gas-tight fit. Easy, quick-twist attachment. Threads are 3", 3 1/2", and 4" to fit most common sewer ports. Clear construction lets you easily and quickly know when your tank is full and in need of cleaning. Accommodates six types of sewer connections Clear construction allows easy viewing of tank | Valterra EZ Coupler 90 °Clear Bayonet Sewer Fitting