Univent Automatic Greenhouse Vent & Window Opener from ACF Greenhouses
Amazon.com: G-More Greenhouse Automatic Window Opener Automatic Vent Opener with Double Spring Solar Vent Roof Opener Replacement Cylinder Temperature Control, with Solar Power Sensor (Window Vent Opener) : Patio, Lawn & Garden
Solar Heat Sensitive Automatic Greenhouse Window Opener Hothouse Vent Openers Auto Vent Kit Garden Tools- (Two Springs,Lifts 15 Lbs,No Power Needed) - Walmart.com
CANOPIA by PALRAM Automatic Hybrid Greenhouse Vent Opener in Silver 701338 - The Home Depot
Bayliss MK7 Triple Spring Autovent Automatic Vent Openers from ACF Greenhouses