Belwith has lead the decorative hardware industry in design, craftsmanship and innovation since 1893. They have been bringing the very best decorative and functional hardware products to your home, with the highest quality. Single Cylinder Bolt. Interlocking deadbolt with double cylinder. Locks door to jamb to prevent forced entry. 5 pin tumbler. Locking cylinder requires a 1-1/4" hole. Includes tamper resistant shutter guard.