Years of experience, have taught us that even the highest quality manufactured acoustic door can quickly be compromised when not supported by compatible, quality hardware. To ensure you receive maximum performance from your KriegerSonic® door, our engineers have developed products and recommendations to help you plan your hardware needs. CAM Hinges CAM hinges included with KriegerSonic assemblies, STC-45 and above. Thresholds Thresholds included with KriegerSonic doors, STC-45 and above. Closers Review our list of recommended closers. Locks Find out which locks retain sound ratings. Flush Bolts Find out what flush bolts to avoid. Panic Devices Learn to install panic devices.