Black PVC 4" 110 mm solvent soil fittings, commonly called 4" solvent soil.

Outside of the pipe and inside of the fitting should be around 110 mm.

Designed to be used with solvent cement for a watertight seal.

Available in many different styles of fittings, please see picture and selection list.

Spigot means it is the same size as the pipe. i.e. a socket goes over it.
See separate listing for actual pipe lengths.