Baffles are used for ventilation to channel cold and hot air to roof vents and to keep insulation from blocking the soffit area.Poly-Vent Baffle are light-weight, flexible, economical and are easily installed with staples. The vents are 48" long. They are 22" wide, including a staple flange on each side, for use in 24" on center areas. The 22" wide vents are perforated down the center, so that the vent can be snapped in half for use in 16" on center areas. They won’t warp, rot or discolor. The 22" vents (doubles) are sold in bags of 50.