Help identifying bathroom sink part

[u/Calm-Explanation-127]

Added some pictures of the old part that came off today. Any help would be appreciated!

[u/rovdog]

Measure the diameter of the head and buy a new slotted Basin Waste from Screwfix. They are cheap and easy to fit.

https://www.screwfix.com/p/flomasta-slotted-sprung-basin-waste-66mm/168jn?ref=SFAppShare

Do away with the foam washer that sits between the trap and the sink and use a good quality silicone. I’d also recommend to get a seal kit and do away with the original seals.

https://www.screwfix.com/p/thomas-dudley-ltd-basin-waste-seal-kit-3-piece-set/8795r?ref=SFAppShare

[u/PANDROSIMO → u/rovdog]

A great answer. I love that so many queries are comprehensively answered by a single good comment on this sub. Thanks