The BSA Sweet scopes use trajectory compensation technology that was originally designed for military sniper. They feature a quick change turret system specially calibrated for multiple grain weights for the calibers .17HMR .22LR .223 .243 .270.The BSA Sweet 17 AO features a long eye relief for comfortable viewing an adjustable objective as well as the preferred 3030 reticle. It comes standard with 2pc dovetail rings and fully coated antireflective lenses all in a onepiece aluminum housing.