The Sig Sauer ROMEO1PRO brings a new level of durability and performance to the miniature open-reflex red dot sight. Its aircraft grade aluminum housing ensures corrosion resistance under the harshest environments, and a new upgraded point-source emitter provides increased brightness in day or night conditions with 12 brightness settings. The molded glass aspheric lens has upgraded high performance coatings for superior light transmittance and zero distortion giving you fast, responsive target acquisition and accuracy. The ROMEO1PRO includes a ruggedized protective shroud in the box for extreme durability. ROMEO1PRO is Compatible With : M17 P320-M17 P320 XFive Legion P320 XCompact P320 XFull All PRO-CUT Slides P320 Pro Series Molded glass aspheric lens with high-performance coatings for superior light transmittance and zero distortion 3 or 6 MOA red dot with multiple brightness settings for rapid target engagement under a full range of lighting conditions TruHold Lockless Zeroing System that utilizes twin adjustment springs designed to endure handgun recoil and return to zero shot after shot Point-source emitter provides exceptional brightness with 12 settings (10 Daytime/2 NV), and 20,000+ hours of runtime MOTAC (Motion Activated Illumination System) that powers up when it senses motion and powers down when it does not Aircraft grade CNC Aluminum housing ensures a lifetime of reliable service Dependable waterproof (IPX-7 rated for complete water immersion up to 1 meter) and fog proof performance Ruggedized protective steel shroud included for extreme durability SIG SAUER Electro-Optics Infinite Guarantee and SIG SAUER Electronic Component Limited 5-Year Warranty