Feature: 1. Wide Compatibility: This Duplex MMDVM hotspot board supports for DMR, for P 25, for D Star and for System Fusion. works with for Orange PI and supports duplex mode and simplex mode. 2. Easy Setup: Pre installed software for Pi Star on the memory card, no need to download again. Upgrade radio frequency (UHF: 430‑440), no need to set for RXOFFSET and for TXOFFSET, they default to 0. 3. Radio Frequency: MMDVM hotspot voard supports UHF 430‑440MHz in duplex mode, UHF 430‑440MHz and VHF 140‑150MHz in simplex mode. optimal adjustment: tx=0, rx=0, no offset required. 4. Easy Charging: Duplex hotspot board provides a free micro USB charging cable to charge with the power bank or connect to a laptop or computer. The hotspot can also work on the move in your car if you tether it to your cellular network. 5. Note: When you flash the memory card with the new version of the software, please don't copy it directly on the memory card, please use the write tool to write the software on the memory card. Specification: Item Type: MMDVM Hotspot Board Material: Iron Color: Black Support: for DMR, for YSF, for P 25, for D Star and System for Fusion Mode: Duplex Mode and Simplex Mode Radio Frequency: Support UHF 430-440MHz in Duplex Mode, Support Both UHF 430-440MHz and VHF 140-150MHz in Simplex Mode Optimal Tuning: TX=0, RX=0, No Offset Performance: High RF Performance Antenna: 2 External Antennas Fan: Cooling Fan on the Bottom On Board LED Display Status: On Board LEDs Show Status, Status Wording on the Housing (TX, RX, PTT, Mode) Memory Card: 8G (included). Package List: 1 x MMDVM Hotspot Board2 x Antenna1 x USB Cable3 x Test Components Note: The difference between duplex and simplex: In duplex mode, there are 2 time slots, Tx and Rx can be done at the same time.