... 1. 4'' 6'' 8'' 10'' 12'' Non-insulated air duct 2. Standard Length: 25 feet 3. Durable construction for ... lasting performance Ventilation Accessaries, Non-Insulated Air Duct 4'' 6'' 8'' 10'' 12'' Available ·Technical Parameters:* ... including grow tents, reflectors (air cooled, cool tube, adjust a wing, etc.), ventilation products (flexible duct inline fans, etc), grow ...