Sennheiser E912 S Polarized Condenser Microphone - Black The e 912 S can be switched on and off via an integrated programmable membrane switch. Mounting slots for fixed installation in tables, lecterns, etc. Extremely rugged sound inlet basket with shock absorbing rubber base An internal DIP switch bank provides the following features: on/off (factory preset), push-to-talk button (PTT), push-to-mute button (PTM) or permanently switched on (ON) 10 year warranty