The 6400 Series electric door strike is designed to be highly configurable to fit almost any mortise or cylindrical lock. As a 3-hour UL 10C listed strike, it provides a fail-secure only solution for fire-rated openings. The strike allows installers to insert and lock in place the deadbolt keeper, or the plug and dead latch ramp, anywhere within its 3-1/8" vertical opening to suit latchbolt position and functional needs Combined with horizontal adjustability, this makes the easy-to-install 6400 Series a good fit for installations where misalignment or a tight fit may be a problem.