"DH-S4220-16GT-190
20-Port Managed Desktop Gigabit Switch with 16-Port PoE
> Transmits data at a high speed through USB 3.0.
> Layer 2 network management PoE switch.
> Supports web, and network management software based on SNMP.
> Network redundancy: STP/RSTP.
> Supports PoE power consumption management, PoE power off management.
> Supports IEEE802.3af, IEEE802.3at.
> Port 1 and port 2 support IEEE802.3bt, and are compatible with Hi-PoE.
> Supports PD alive mode.
> Supports 250 m long-distance transmission mode."