SmartBaffle is constructed of non-collapsing material with lifetime durability. Ease of installation by the contractor is achieved by the design, engineering and technology inherent in the baffle product. Designed for rafters that are 24 inch on center. If you are looking for Baffles for rafters 16" on center, follow this link to the SmartBaffle 16 page Shipping costs per box $24.95 Please use the Pieces option below to select the thickness you require.