OMNITRONIC STR-500 is a UHF in-ear monitoring bodypack receiver for the IEM-500 system, operating from 863–865 MHz with 16 switchable frequencies. It provides stereo headphone output through a 3.5 mm jack, adjustable left/right balance, selectable high-frequency boost, pilot-tone squelch, a lock function, belt clip, charge-status indication and RF signal-level display. The receiver uses two included 1.5 V AA alkaline batteries and measures 16.5 × 2.3 × 6.4 cm, weighing 0.14 kg.