Additional 4" plenum rated riser tube for the CPP-4 and CPP-4-H cable penetration plates. These additional riser tubes are used in conjunction with the ceiling entry plates by Cable Tech Solutions. The ceiling entry plates hold 4" conduit in place and sits above a ceiling tile so you can easily and discreetly hold up to 3 or 6 conduits in a 2" x 2" ceiling tile. Maximum recommended ceiling tile thickness is 5/8".