LANCER SHOTGUN EXTENSION TUBEMOSSBERG 590 PLUS 6FEATURES-Adds 6 rounds to capacity-Length: 14.5"-Designed to attach to existing shotgun magazine tubes to provide added capacity to the shotgun-Machined aluminum components combined with a lightweight carbon-fiber tube-Creates a lightweight, durable extension to your shotgun-An extra-long spring is included that can be cut to optimize loading-Extension clamps are recommended for extension tubes that extend beyond the end of the barrel