This tamper-resistant Panther Lower Unit Locking Kit is designed for Yamaha 150HP Dual Engines. Keep your boat engine's lower unit safe from theft. These tamper-resistant bolts and nuts replace your existing lower unit bolts and nuts. Both require the unique tamper-resistant tool to install and remove. Each bolt has a unique pin configuration to deter even a professional thief. The high-strength Bell Washer protects against utilizing any other clamping device to remove the bolt and/or nut, deterring the boldest of thieves. Constructed of marine-grade stainless steel for strength and corrosion resistance. Requires unique tamper-resistant tool to install & remove High-strength bell washer protects against other clamping devices Constructed of marine-grade stainless steel for strength & corrosion resistance | Panther Lower Unit Locking Kit for Yamaha 150HP Triple Engine with 30" Shaft