The internal micrometer adjustments securely lock to prevent any unintentional changes to the sight settings. The design ensures there are no obstructions that could hinder or obscure the shooter's field of vision. The device weighs a mere 1.5 oz. It features standard hole spacing, compatible with rifles that are factory drilled and tapped for receiver sights. The Foolproof-TK model is equipped with target knobs. The Foolproof-TK receiver sight incorporates precise internal micrometer adjustments, designed to lock securely and prevent any unintentional alterations Compatible with the Marlin 336 and similar models, this product features standard hole spacing, ensuring straightforward installation on factory-drilled rifles Weighing only 1.5 oz, the sight features target knobs that improve precision while maintaining an unobstructed field of vision for the shooter