sr555The SR555M SmartMount TM Flat Panel Video Conferencing Trolley has been desned to include all of the features you may need, making it perfect for any location. The mobility ofThe SR554 is a low-noise, transformer-coupled preamplifier optimized for source impedances between 0.05 Ω and 1 kΩ. With an input noise of only 0.1 nV√Hz, the SR554 can be used in a