Window Opener Single Spring Greenhouse Temperature Control Auto Vent Opener

Features:
Elongated aluminum cylinder with paint spraying, weather resistant.
Solar heat sensitive vent opener, automatic stretch or shrink the vent while the temperature is changing.
Stainless steel accessories would last long time use.
Aluminum frame looks more lustrous, durable and rust-proof.
Easy to install, universal fit for all aluminum frame greenhouse.
Auto-opening temperature range is adjustable from 15-25℃(60-77℉).
Maximum opening at about 30℃/86℉(depending on adjustment and load).
Suitable for the vents weighting up to 7kg/15lb.