L-com's exclusive rack mounted harmonica cluster bars organize all your telecom cables into a convenient rack mounted panel. Each panel uses 2, 3, or 4 of our harmonica cluster bars with a Telco female RJ21 50-pin connector on the back and up to 12 RJ ports on the front. Each panel is constructed with black powder coated steel with screened write-on spaces for years of reliable service. Each RJ21 Telco connector is secured to the back of the cluster bars with a hook and loop style strap.