Gm 600b professional wireless microphone

Based on the search results, the "GM-600" refers to a professional wireless microphone system, with some listings specifically describing it as a

GM-600 Wireless Microphone with a 100-200 meter range for high-quality sound production. 

However, search results show similar products often listed under slightly different names like "AM-600" or within the UHF 600-699MHz range, which are generally characterized by the following features: 

Core Features and Specifications (Typical GM-600/600MHz Class)

• Technology: UHF (Ultra High Frequency) Wireless technology for stable, low-latency, and anti-interference transmission.
• System Type: Usually available as a handheld dynamic microphone or as a dual-channel system.
• Construction: Often features a durable metal or alloy, wear-resistant design.
• Sound Quality: Professional dynamic mic core with high-fidelity sound, often featuring anti-howling and noise reduction.
• Operating Range: Long-distance, often cited between 50 to 200 meters, depending on the specific model and environment.