Mighty Mule Automatic Gate Opener for Medium Duty Single Swing Gates for 16 Feet Long or 550 Pounds (FM350) The FM350 is Mighty Mule's most popular gate opener! Mighty Mule's most versatile single swing gate opener for gates up to 16 ft. long or 550 lbs. Perfect for all gate types including ornamental, chain link, tube, panel, vinyl and wood. 12 - Volt Automotive or Marine Type Battery Required. Easy DIY (Do It Yourself) installation that includes an interactive DVD for added assistance. All-inclusive kit that does not require welding or an electrician. 30% Residential Energy Efficient Property Tax Credit available! Residential home owners can use this credit on a new operator system, accessories and installation with the purchase of a Mighty Mule 10-watt Solar Panel (FM123). Backed by a 12 month Mighty Mule Warranty and Technical Support.