Killer Instinct DSC Compact Narrow Ld Sled Dead Silent Crank 100% silent operation Aluminum alloy Compatible with: Killer Instinct crossbows featuring the Let-Down Trigger Box All X-Cam models Boss and Burner models Aluminum barrel models from 2019 or newer Not Compatible with: Wide composite barrel models prior to 2025 Lethal Series Fiery Series Bone Collector 405 Fierce 405 Ano Hero SWAT Series Ripper 415 KI Series Models produced prior to 2018