Todays Tools Plumb Tub - Radiator Drain Tub (PT) The PlumbTub is the ultimate solution for all your radiator draining needs. Its innovative design, flexible flanges, and compatibility with various pipe sizes make it a versatile and reliable tool that you can count on. Helps prevent unsightly stains on carpets and floors Suitable for 10mm, 15mm & 22mm Copper or Plastic Pipe Sizes Snap clip holds tub in position for draining of radiator Resistant to most chemicals Strong flexible PVC construction allows tub to be compressed to fit under low hung radiators Bendy and flexible, meaning it can be used at many different angles Holds 1.4 litres of water