Features: Mesh Intercom 2.0 Technology Compatible only with other Mesh equipped intercoms (30 and 50 series Sena units for example) Multi-channel open mesh intercom (up to 9 channels) Bluetooth 5.1 Low-profile design Simplified jog dial and two button layout Hands-Free Profile (HFP) Advanced Audio Distribution Profile (A2DP) Voice prompts can be commanded by 11 different languages (switching firmware with each language) Mesh Intercom: Working distance up to 2.0 km (1.2 mile) in open terrain HD speakers Music sharing Audio Multitasking Charging time: 1 and a half hours for full charge equals 11.5 hours of mesh talk time Advanced Noise Control Built-in SBC Codec Wide volume control Smartphone app Note: Sena Spider ST1 units are not Bluetooth intercom capable. The ST1 can only be paired with other Mesh Intercoms