 CQS FRONT AND BACK MODULES|SEL-4CQS1-S 4x4 or Dual 2x2 CQS Clean and Quiet SDI Switcher, line sync or frame sync mode, includes single back module with two HD-BNC input connectors, two inputs on SFP (SFP+2ERX+NR+L dual HD-BNC input SFP included) and four HD-BNC outputs, GPI and serial data port, optional SELOPT-CQS1-SK-SLS software key license adds a 2x1 Slipless Switching mode |