How it works.
Four flexible silicone sealing ribs form a one-way valve. Water passes through freely under gravity. When flow stops, the ribs close to create a continuous mechanical seal. No water required.
The GD25 is sized specifically for Australian 2.5" (DN65) drain standards, accommodating pipe diameters from 63 to 65 mm. This size sits between the GD2 and GD3 and is not available outside Australia.
Drop-in installation. No tools. No plumber.