RS20 unmanaged OpenRail switch, 8x, 9x, 16x, 17x, 24x and 25x ports (only 4.5 inches)> Up to 3X fiber ports> Redundant power inputs via dual 24V DC pluggable terminal blocks> Fault relay> Multimode (MM) and singlemode (SM) fiberoptic ports> 61850-3, IEEE 1613, EN 50121-4 and ATEX 100a Zone 2> cUL 508/1604 Class Div 2 (MIL-HDBK-217F)