British General Cordgrip Lamp Holder BC - Screwfix
Bayonet B22 BC Ceramic Lamp Bulb Holder With Side Fixings, Replacement Coughtrie | eBay
B22 to E27 Socket Adapter, Bayonet BC Cap B22 To E27 ES Edison Screw Converter, BC to ES Extend Lamp Holder Base, B22 to E27 Adaptor Holder Fitting 0-250V, 2A Lamp Socket
25+ Types Of Light Socket Adaptor Base Converter Extender Lamp Holder Bc Es Gu10 - Lamp Holder Converters - AliExpress
Metal BC B22 Bayonet Cap Bulb Lamp Holder M10 Vintage Retro MLH004 lampholders | eBay
Lamp Holder | BC | B22 | Bayonet Cap Lamp Holder Unswitched Made In The UK | eBay