Have an outdoor gate or swing door opening you are hardwiring for keypad or card access?  Then this Grade 1 industrial strength, all weather strike is exactly what you need.  The Trine EN400 will buzz open/open (AC input voltage required for buzzing sound) from a telephone release, , , , or .  Upon being energized, its keeper lip is released, enabling the visitor to simply pull or push the door, or gate open and enter.