“Sightron Inc SIIISS624X50 SIIISS 6-24x 50mm 6.1-3.9ft@100yds 1″” Tube Blk MiAll scopes in the SIII series feature a 30mm one-piece Main-Tube made fromhigh quality Aircraft aluminum. Tube thickness is more than twice as thickas one inch models to provide maximum rigidity. All models are fogproof,shockproof and waterproof. Large oversize target knobs with 1/4 inchadjustments are standard on all models. All models feature target knobsthat are re-settable to zero. All target knobs are protected by large heavywindage and elevation caps.”