With the Juliana automatic window openers, you can be sure of an even temperature in your greenhouse day and night. They allow thermostatic ventilation control through the roof windows of your greenhouse. Although two solar-powered models are available, DoItYourself.com only recommends the Univent, which is spring-loaded for a tight closure and allows more accurate thermostatic ventilation control through the roof windows of your greenhouse. Univent
Replacement cylinders are available. The hydraulic cylinder is warranted for 12 months and has a normal life of 3 to 4 years, depending on atmospheric conditions.
JUA4021 Valued at $59.95 plus shipping - Sale Priced - $49.00 - Freight Free with Greenhouse Order
Replacement Cylinders for Univent JUA4051 are $27.00 each - Sale Priced - $23.00 - Freight Free