The Premier Manual Defrost Freezers feature a microprocessor temperature controller, allowing for precise temperature control, recovery and maintenance versus mechanical style thermostats. Critical samples and supplies are security backed with an extensive package of temperature security and alarms. Manual defrost units (excluding Chest Freezers) also feature insulating inner doors and a manual defrost operating system to limit product-damaging temperature spikes. In addition to the elimination of damaging auto defrost cycles, the inner doors help reduce cold air loss during main door openings and greatly improve temperature recovery. *Periodic manual defrosting is required.