This is a 304 Grade Stainless Steel Ball Valve 1/2 BSP Female x 1/2 BSP External Welded Thread. Often used to convert a keg into boil kettle, also known as a keggle.
1 x 1/2" Ball Valve with 1/2" BSP male & female thread
1 x Recessed 1/2" Nut
1 x Silicone Washer (used on the inside of vessel)