Halo® H99TAT Recessed Air Tight New Construction Housing, 4"Small new construction aperture for non insulated ceilings or where insulation can be keeps 3" from housing. Housing features an integral thermal protector to guard against misuse of insulation materials or improper lamping. Pre installed and captive bar hangers on the housing can be positioned to any point within a 24 in. joist space. These bar hangers also fit onto T Bars for easy installation into drop ceilings. This housing's 5 1 2 in. height