The DPTEK DK3310MI-8T4S-2FB is is a specialized industrial managed bypass switch featured with 8-port 10/100/1000-T RJ45, 4-port 1G/2.5GBase-X SFP and 2 channels single LC Bypass or 1 channel dual LC Bypass. In normal operation, it is a L2+ managed Ethernet switch. It supports ERPS redundant network and the self-recovery mechanism less than 20ms on full load which allows you to scheme a reliable Ethernet network by building a redundant ring topology as your back-up solution.
Refer to above PDF Data sheet
Part number – DK3310MI-8T4S Industrial DPTEK 8 Port Gigabit L2 Ind. PoE +2 SFP