7, the MK. 7 Triple Spring, the Mk. 7 HYDRAULICHECK, the Mk. 7 Super and several autovent models from Thermofor - a standard model and a heavy duty double spring model for use in exposed locations.
Bayliss XL Autovent Automatic Greenhouse Window Opener Solar Roof Vent Opener
Bayliss XL Autovent Automatic Greenhouse Window Roof Vent Opener Auto Vent
Bayliss MK7 Autovent Automatic Greenhouse Vent Window Opener
Bayliss Mk 7 Greenhouse Window Autovent Automatic Opener Auto Vent Green House
Bayliss XL Solar Greenhouse Automatic Window Opener Auto Roof Vent green house
Replacement Cylinder for Bayliss XL Greenhouse Window Automatic Vent Openers