Arriving Early Fall 2021. The American made Pentagon OTF is designed to meet the exacting demands of users who require a dependable one-handed, fast opening knife. SOG’s Dynamic Lock-up System redefines open reliability and blade lock-up strength in OTF knives, while the CRYO S35VN blade and hard-anodized aluminum handle reinforce the durability of the knife. Pentagon OTF delivers reliable OTF technology for professional users who rely on high-end steel and technology. Part # 15-61-02-57