Long lasting, efficient ultra-bright white LEDs. * Adjustable LED lamp heads provides optimal center-to-center spacing. * Charge rate/power "ON" LED indicator light and push to test switch for mandated code compliance testing. * Internal solid-state transfer switch automatically connects the internal battery to LED lamp heads for minimum 90-minute emergency illumination. * Surface mount via quick-connect back plate; fits most standard size junction boxes and snaps into place to make internal electrical connections.