Only For Mini Duplex BoardSet Up Pi-Star Software And for Raspberry Hardware (RPI 0-3) New Pi4B Needs To Delete Right SocketPi-Star General Configuration Of Mmdvm_duplexSet Controller Mode: Duplex Repeater Or SimpleThe Default Bit Error Rate Is Less Than 5%, And The Default Offset Is 0. If The Bit Error Rate Is 5%, As Long As The Signal Can Be Received, It Can Be Corrected Through Offset.Radio frequency: Freq:144-148, 219-225, (main frequency band) 420-475, 842-950Duplex mode:Example:RX:438.000000 TX:433.000000Duplex mode:Example:RX:145.000000 TX:433.000000Simple mode:Example:RX:438.000000 TX:438.000000Radio/Modem Type:STM32-DVM/MMDVM_HS- Hat(GPIO) or any other (GPIO board)AdminExpertEdit MMDVMHOSTRXOFFSET=0 TXOFFSET=0 (default value in pistar) (Update:2019/2 new 3225 TCXO so the offset is 0)Update new firmware:(pi-star / Expert / ssh access / user :pi-star pass:raspberry)sudo pistar-mmdvmhshatflash hs_dual_hatNote:Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The UseColour:As ShownMaterial:PCBPackage Contents:1 * Hotspot Board Module2 * Pin HeaderOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.