Sennheiser XSW 2-835Overview
XSW 2-835-A Wireless Handheld Microphone System with e835 Capsule (A: 548 to 572 MHz)
The unit has automatic frequency management and synchronization so you don't have to scramble to find an available channel. The transmitter's e835 capsule uses a cardioid polar pattern, which is part of the evolution series and designed for withstanding tougher, live-stage conditions.