The Acro Mount Mk2 is available in three heights: 1.54", 1.93", and 2.26". The 1.54" height provides a lower one-third sight alignment, allowing standard height iron sights to be visible in the lower portion of the red dot optic window. The 2.26" height aligns with common magnifier mounting systems. Standard height iron sights are visible beneath the optic only when using the 2.26" mount. The 1.93" and 2.26" height mounts include an integrated accessory interface compatible with various accessory mounting platforms. Weights (including screws) are as follows: 1.54" – 2.5 oz 1.93" – 2.7 oz 2.26" – 2.8 oz Length: 1.98" Each mount is CNC machined from 7075-T651 aluminum and finished with MIL-A-8625 Type III hard coat black anodizing. An optional FDE Cerakote coating is applied over the hard coat anodizing. The mount includes all necessary screws to attach the optic. Assembly requires a T10 Torx driver to secure the optic to the mount, and a T27 or IP27 Torx driver to attach the mount to a Picatinny rail. Recommended torque specifications: Picatinny clamp – 50 inch lbs (5.7 Nm) Optic to mount – 25 inch lbs (2.8 Nm) Hardware: One 10-32 x 1.25" Torx socket cap screw. This product is covered by U.S. Patent No(s). D1027098 and other pending patents. Made in the USA.