The Verplas Self-Seal Coupling® eliminates the need for sealant and tape by ensuring that the air leakage in or out of the duct joint is kept to an absolute minimum. This unique design provides consistent joint quality and integrity and couples conventional ducting and fittings together to form an almost airtight installation. It significantly reduces installation time and can be removed and re-made for alteration, maintenance and cleaning. The sealing ability of the couplings has been independently tested by the Building Research Establishment in Test Reports 285430, 691696, 288446, 291695, 691697 and 298279, which are available on request. Please note that the Verplas Self-Seal Couplings have been designed to suit Verplas ducting only. (Please note with use of Verplas Ducting only).