Marcrist Turbolite 38 x 165 1/2 in BSP (F) Core Drill MRCTLDC38 Turbolite Dry core bits for use with machines with 1/2in BSP male fittings:Drills:Aerated ConcreteLondon BrickBreeze BlocksBlock PaviorsConcrete BricksSet StonesSize: 38 x 165mm MRCTLDC38