Brass 1/2 inch low pressure BS1212/1 part 1 float valve (also known as a ballcock, inlet valve, fill valve or ball valve).
The internal components of this ballcock valve are larger than those in the high pressure version, to allow a better flow of water.
Threaded ball mounting end has 5/16 inch British Standard Whitworth (BSW) thread - use standard 4-1/2 or 6 inch float.
Normally used in gravity (tank) fed applications, such as older toilet cisterns.
** BSP thread sizes are measured a special way - have a look at our information page for more details **