A plumber's third hand. Centralising, anti-swivel, acrylic washers. Double sided adhesive washer sticks the tap or fittings in place leaving both hands free for threading and tightening backnuts. Universal size for 1/2in. and 3/4in. taps, monoblocs, tank connectors, ball valves and toilet seat fixings. Time saving when installing new taps. Essential when replacing old taps and fittings in-situ. Double up for undulating china surfaces. External diameter 50m, Internal hole size 21mm. Cut incisions for larger hole diameters. Watch Tap Installation with Stiffnuts and Stikfast video on You Tube . Buy MON581 from Amazon Marketplace.