Nissan Skyline RB20,RB25,RB26,RB30 & Holden VL RB30 Welsh Plug KitStainless Steel MaterialBrand: AEROFLOWPart Number: AF3000-1007Description: These Aeroflow Performance welsh plug kits are designed for sealing up the casting core holes in your engine block. The expansion plugs help protect against cracks caused by the pressure of frozen coolant and in regular operation will ensure that allvital fluids stay in the engine, where they belong. These complete engine block freeze plug kits include Stainless Steel Welch plugs and steel oil gallery plugs but do not include cylinder head plugs if required. Each kit is specifically designed to suit each make and model with all correct sizes included for when you are rebuilding your engine. Additional Specifications: Kit Includes:1 x 50mm Outside Diameter1 x35mm Outside Diameter12 x 30mm Outside Diameter7x 22mm Outside Diameter3x 20mm Outside Diameter