This waste water wye (Y) or ell (L) allows for your gray water (sink, shower) and black water (toilet) to flow together just before your 3" sewer hose connection.
Both the 3" black waste side and the 1-1/2" gray water side are flanged. The flanges are designed to bolt to modern Valterra slide valves.
The hose connection outlet has the bayonets that are standard for Valterra hoses and caps.
We recommend purchasing a cap, a 3" valve and a 1-1/2" valve at the same time.