Boss connector 4 x 1 ½

It looks like you're looking for a 4" x 1 ½" Boss Connector. This type of connector is typically used in drainage systems to join pipes of different sizes. Here are a couple of options:

1. McAlpine 4" x 1 ½" Mech Soil Pipe Boss Connector: This black mechanical soil pipe boss connector is designed for pushfit or solvent weld waste pipes. It's a universal connection suitable for various applications.

2. Juma Plastic Boss Connector: Available in gray, this connector is part of a range of solvent fittings for soil, waste, and sewer systems. It's designed to meet British Standards and is suitable for various plumbing needs