Railcar Unloading Connectors install between the rails to help provide a clean, safe material unloading from railroad hopper cars. Dual, air-over-hydraulic lift cylinders push HD boots with sponge seals securely up against the hopper car unloading gates to provide a tight, clean transfer of material from the railcar to an undertrack conveying system. Connectors: 1. Prevent material loss; 2. Reduce air pollution and contamination; 3. Eliminate the risks associated with crawling under railcars; 4. Automatically maintain a tight seal as the railcar rises as it empties.