The Heddolf ER294-KB by Keystone is a compact single channel long range gate opener radio receiver with a range of up to 1,500 feet. This receiver has 10 dip code switches that allows for 1,024 code combinations and operates on either 12 or 24 volt AC or DC selected by an internal switch. The output is a form "C" N/O, N/C dry relay contact closure that is selectable for either an adjustable 0.8 to 2 second pulse closure or maintained contact closure with remote control signal output that is selected by an internal switch. The Heddolf ER294-KB radio receiver has a green wire antenna as well as an F-connector for adding an optional remote antenna (Digi-Code 5166 sold separately) to achieve better range by having the antenna outside metal enclosures and as high as possible. Operating on the 433MHz frequency and using crystal control RF circuitry provides for very stable operation with no frequency drift and maximum range. The Heddolf ER294-KB is only compatible with the Heddolf EX220-1K or EX220-1KB remote controls Product Features: Controls up to one garage door or gate opener Long range operation up to 1,500 ft Operates on 12 or 12 Volt AC or DC Form "C" N/O and N/C isolated contact Selectable 0.8 second pulse or maintained with signal contact closure Wire lead antenna and F-Connector for optional remote antenna (not included) One-Year manufactures warranty Product Specifications: Power: 12 or 12 Volt (switch selectable) AC or DC Frequency: 433MHz Codes: 1,024 (set by 10 dip code switches) Dimensions: 4.25 x 3.0 x 1.25 inches (excluding mounting tabs and F-connector)