Huawei S5720-28X-SI-DC(24 Ethernet 10/100/1000 ports,4 of which are dual-purpose 10/100/1000 or SFP,4 10 Gig SFP+)

-5??C to +50??C (23??F to 122??F) at an altitude of 0-1800 m (0-5906 ft.), NOTE: When the altitude is 1800-5000 m (5906-16404 ft.), the highest operating temperature reduces by 1??C (1.8??F) every time the altitude increases by 220 m (722 ft.). The equipment can operate beyond the normal operating temperature range for a short-term period, but the following conditions must be met: The equipment operates at a temperature of over 45??C (113??F) consecutively for at most 96 hours in one year. The equipment operates at a temperature of over 45??C (113??F) for a total of no more than 360 hours in one year. The equipment operates at a temperature of over 45??C (113??F) for no more in 15 times in one year. The equipment may be damaged or experience unexpected exceptions if any of the preceding limits is exceeded. The equipment cannot start when the temperature is lower than 0??C (32??F). The maximum distance of optical modules used in these conditions cannot exceed 10 km.