The bit where your crank spindle goes through your frame.
There are many many variations of bottom bracket. Here are a few more common ones we carry in stock.

Sram
Sram BB GXP Team Cups English Thread Inc Bearings 73/68 - 00.6415.045.000
£34
Currently Unavailable
Shimano
Shimano BB-R9100 Dura-Ace HollowTech II bearing cups - 68 mm English thread
£49.99
Currently Unavailable
Truvativ
Truvativ Bottom Bracket - Power Spline 113 X 68mm - 00.6415.005.000
£23
Currently Unavailable
Wheels Manufacturing
Wheels Manufacturing Pressfit 30 To Shimano 24mm Crank Spindle Shims
£34.99
Currently Unavailable
Wheels Manufacturing
Wheels Manufacturing BB30 Service Kit With 2 Clips And 2 X 6806 Bearings
£27.99
Currently Unavailable