It much convenience to make for charcoal grill , bbq , campfire and , great for outdoor barbecue and picnic Air Duct Diameter : Approx.47mm / 1.85 This fan does not need electricity , , widely used in leisure barbecue , , small stove and so on Hand crank blower has strong structure , small size , light weight , large wind and beautiful appearance No battery , no additional firewood required, Manufacturer: Watreketal