Replacement Power Tube to fit the Mk 7 Standard, Mk 7 Triple Spring and Mk 7 Hydraulicheck Autovents. Length excluding piston : 7.38″ / 18.75 cms.
The standard tube is filled with a wax that enables the window to be set to start opening between around 12oC (55oF) and 18oC (65oF). We also manufacture a tube that can be set to start opening the window at about 70oC. This is called a Mk 7 Orchid Wax tube.
If your autovent is very old, you may also wish to consider purchasing the Mk 7 Spacer Set which contains all the spacers and washers for the Mk 7 autovent.