The Trijicon TA31RCO-M150CP-G ACOG 4x32 Rifle Scope with Green Chevron BAC Reticle was built and designed for the US Army M150 Rifle. No tools are needed for windage and elevation adjustments because the TA31RCO-M150CP-G features external windage and elevation adjusters, making it waterproof up to 11m without caps.