Apkr-gm-2km likely refers to a gps geometer receiver with a 2km range, specifically designed for agricultural applications. it is a dual-frequency gm smart gnss rtk l1/l2 receiver, meaning it can receive signals from multiple satellite systems (gps, glonass, galileo, beidou, qzss, irnss, sbas) and achieve high accuracy using rtk (real-time kinematic) technology. the "2km" likely indicates the typical communication range for its built-in lora radio modem or other wireless connection, allowing it to receive corrections from a base station or cors network within that distance.