The Black Arts Design Parallax Throw Lever is designed to aid the competitive shooter and hunter in quick adjustment of parallax settings. The long arm serves as a tactile 'zero stop'. A user can set their parallax at a preferred distance, position the long arm in a particular position, i.e. aligned with the elevation turret, and lock it in place with the two M3 cap screws. Once the position is set you can return to this 'zero' position without ever taking your eye off target. The shape and design allow parallax adjustments to be made with one finger, the thumb, or even the palm of your hand. Left-handed shooters can easily adjust parallax with their support hand over the top of the scope. Aggressive texturing ensures a positive grip, and the rubberized adapters provide a rock-solid fit and allow our parallax throws to be swapped from scope to scope. Material: Carbon Filled (CF) PETG CF PETG was selected for low shrinkage, resistance to heat, and high dimensional accuracy. The addition of carbon fibers increases flexural modulus (stiffness) well above standard PETG. TPU (thermoplastic Polyurethane). TPU is extremely flexible and highly resistant to abrasion. Brass Heat Set Inserts Create robust attachment points and allow for a clean appearance. Features: Functions as a tactile 'zero stop' for the parallax knob. Highly textured surface to ensure a tactile non-slip surface even in wet conditions. Allows left-handed shooters to adjust parallax with their support hand. TPU adapters provide a solid and secure fit and allow one wheel to be swapped among scopes (scope-specific adapters can be purchased separately). The asymmetrical design allows magazine clearance (depending on scope position, ring height, and rifle model) on left-side loading rifles.