The Killer Instinct Dead Silent Crank Compact-Narrow LD Sled in Black allows 100 percent silent operation with a compact body that rapidly attaches and detaches in seconds to safely and silently cock your crossbow. Its compact size ensures ease of carry. It is compatible with Killer Instinct crossbows only. Additionally, it works with models with let-down trigger box, all X-Cam models, Boss and Burner models, and aluminum barrel models from 2019 or newer. It is incompatible with wide composite barrel models, models prior to 2025, Lethal series, Fiery series, Bone Collector 405, Fierce 405 Ano Hero, Swat series, Ripper 415, Kl series, and models produced prior to 2018.