Batson ALPS Centra-Lock Reel Seat The Alps Centra-Lock and Centra-Lock knurled long nut (KLN) aluminum reel seat was their first design of aluminum casting/spinning fishing reel seats. Offered in both standard lengths and knurled long version, this reel seat is the standard when needing an ergonomic casting or spinning reel seat. This exclusive Alps design was first to the market and created its trusted brand name Centrra-Lock. Hearing the direct demands of avid fishing enthusiasts, Alps set forth to CNC machine 6061 T-6 into this beautiful yet durable reel seat. Users will benefit from the inventive dual nut construction and lobed design wih delrin spacers, feeling confident with your favorite reel locked in place. Like all Alps aluminum reel seats, the baseline remains with a hard anodized coating to prevent corrosion.