SPEEDI- BOOT 14 in. x 24 in. x 10 in. ceiling box register boot can be easily and conveniently installed with its pre-drilled pilot holes and telescoping hanger arms. The boot features a dust and debris cover that helps keep dust and debris out of your HVAC system. The register boot is made of zinc-coated galvanized steel and designed for use with wood and metal studs and drop ceilings.