Maximize the PSI for your 58400 Series Power Line Blower with these Series 58200 Duct Seal Kits. Constructed of polyurethane, the 58200-400 kit's expandable seals deliver superior sealing for maximum pressure when blowing in 4-inch conduit. This seal kit is color coded to match the corresponding line dart (sold separately) for easy recognition. Single seals are very difficult to properly align, and double seals are very expensive. Economical and effective, these Duct Seals feature an alignment washer with a single seal. This 58200-400 kit includes the seal assembly, support disc and spacer tube; simply install on your Handle Assembly (sold separately) for maximum sealing and expansion properties without the blow back.