Product Review

A brand new, high-quality replacement cylinder for Greenhouse Window Automatic Openers or Aotovent, as they are commonly called.
Compatible with most greenhouse window openers with either single or double springs.
Replaces the cylinder on all leading autovent manufacturers, Optivent, Univent, Thermovent, Sesam Liberty Vent, Ventomax plus B&Q and many branded and unbranded others we have failed to mention.
Uses solar energy to heat the cylinder pushing the piston out and slowly opens the window, the hotter the temperature, the further the window opens.
Starts to open at 60°F (16°C) and reaches its maximum opening at 80°F (26°C) helping to maintain optimal growth conditions in your greenhouse.
Compare the image with your old opener. If they look the same, they are the same.
Why spend more replacing your complete broken autovent when a cylinder replacement is all that is needed.
Maximum load 15lb.
A simple 5 minute job to replace, see below for a basic guide on how to replace your old cylinder:

Instuctions:
1.) Place new cylinder in cool water or the refrigerator for 30 minutes.
2.) Remove old cylinder by removing the hairpin clip and unscrewing cylinder. Check to see if your window or vent is moving freely.
3.) Screw in the new cylinder and replace hairpin in hole closest to cylinder for wider opening, or place hairpin in hole farthest away from cylinder for a less wide opening window.
4.) Adjustments: You can slightly alter the opening temperature by screwing the cylinder further in for opening at a lower temperature, or out for higher.
5) Always adjust the cylinder at the hottest part of the day to see how far it will open, adjust at a cool time to see at what temperature it will start to open.