The Yeastar GSM Module (1‑Channel) for S‑Series PBX expands your Yeastar S-Series PBX (including S20, S50, S100, S300, and S412) with one GSM voice/SMS channel. It supports quad-band GSM frequencies for global use and integrates directly into the PBX chassis. The module enables mobile trunking, call routing through GSM, and two-way SMS functionality, making it ideal for cost-saving call management and mobile redundancy.

Key Features:

• Adds 1 GSM channel for voice and SMS

• Compatible with Yeastar S20, S50, S100, S300, and S412

• Supports quad-band GSM: 850/900/1800/1900 MHz

• Caller ID, SMS sending/receiving, and call forwarding features

• Easy plug-and-play installation

• Ideal for mobile call routing and GSM fallback in PBX setups

Let me know if you’d like similar content for the 3G/4G mod