This boss pipe is used to introduce a single waste pipe into the soil stack. The boss is already open and tapped with a 2andquot; BSP thread. As our push fit cast iron soil pipes and fittings are all plain ended, sockets are required to connect this boss pipe to a soil pipe.All of our push fit cast iron soil fittings are treated to a factory black two-pack gloss paint finish. The whole range is manufactured in grey cast iron to BS EN 1561.andgt;This soil pipe range is particularly well-suited to installations in public buildings, listed buildings and conservation projects. It is 100% recyclable. Click here to view or download full installation instructions.