The EH2305-1Fm/1Fs has a metal housing with 4 RJ-45 ports and one optical ST/SC port, it’s designed to work in the industrial environment, such as in hazardous locations that comply with CE, FCC, UL and RoHS standards. The EH2305 series protects itself from receiving too many broadcast packets. During normal use, broadcast packets will be forwarded to all ports except the source port. However, it will discard broadcast or multicast packets if the number of those packets exceeds a threshold in a preset period of time. When the preset period expires (about 800ms), it will then resume receiving broadcast or multicast packets until the threshold is reached again. The EH2305 series provides two redundant power inputs that can be connected simultaneously to wide-range DC power sources. If one of the power inputs failure, the other live source acts as a backup to provide EH2305 series the power it needs automatically.