Sentry on September 12, 2015 | Marketing Team Monitor Cue Light Make sure you never miss a cue! The Sentry(4.5" x 1.25" x 1/25") easily affixes to the front of a computer monitor, downstage speaker or podium. Connect to PerfectCue via Cat 5 cable. Dual RJ45 jacks allow multiple Sentry cue lights to be interconnected along a single cable "run." Green, Yellow, Red lights correspond to PerfectCue's USB commands Forward Arrow, Back Arrow and "B".