greenhousestuff.com > environmental control > ventilation > automatic vents > lvr for I-frames > order form

inside shaft size:
1/2" shaft size 3/8" shaft size 1" shaft size
thermostat:
no thermostat one thermostat - $59.00
bracket length:
no bracket 24 3/4 inches - $95.00 30 3/4 inches - $95.00