The VX-5HD is taking optical performance to a whole new level. We gave it a High-Definition optical system for sharpened clarity, and the Twilight Max Light Management System for even greater low-light performance, giving hunters a visible advantage at dawn and dusk when the biggest game is on the move. The new CDS-ZL2 (Custom Dial System ZeroLock 2) elevation dial locks in place so it cannot be inadvertently rotated off zero. A mere press of a button will allow the user to dial up two turns of elevation, if necessary. On the 2nd revolution of the elevation dial, the button sinks in to show you are on the 2nd turn so you can dial for extended ranges and never lose your place. The covered pop-up windage dial provides fast and accurate sight-in and easy rezero. All VX-5HD CDS-ZL2 riflescopes include one free Custom Ballistic Dial with purchase.