You're welcome. From a recent article highlighting the uniqueness of RSCF Cryometriz freezers. Emphasis is mine
"The patented contained-liquid nitrogen delivery system circulates the cold nitrogen within the walls of the freezer, keeping the contents frozen while preventing direct liquid nitrogen exposure to users. A controller opens or closes the liquid nitrogen flow valves to regulate the freezer operating temperature within ± 3°C of the user set point based on a thermocouple placed in the interior sample space. A second, redundant thermocouple is located within the freezer in case the primary thermocouple should fail. The cryogenic refrigeration system rapidly removes heat, allowing the freezer to recover to a -80°C set point temperature in less than 15 min after a two-minute door opening versus a more than 90-minute recovery for a typical mechanical freezer under the same conditions. The Cryometrix freezer uses a small portion of the exhaust nitrogen gas to purge the interior sample space during door open-close events and thereby dramatically reduce the moisture ingress and frost build-up commonly experienced by mechanical freezers. An onboard battery back-up powers the controller and valves for up to 72 hours in case of power outage, and a manual by-pass valve allows liquid nitrogen to flow through the freezer from an onsite tank should power failure persist."