The addition of a small hydraulic damper which we have called the “Hydraulicheck” to the Mk 7 offers the best answer yet provided to the problem of wind damage on greenhouse and conservatory vents. It only allows the vent to be opened slowly but it can be shut quickly.
Whilst the Mk 7 Triple Spring model offers an adequate degree of protection in most positions, the Hydraulicheck fitting is advisable in areas where severs conditions are encountered.
Thy Hydraulicheck is a single acting hydraulic damper fitted between the arms of the Mk 7 Autovent. The resulting unit appears very similar to the Triple Spring model and is identical in size and performance.