What's everyone using? Check these out..
Dope Ropes are a cost effective data card holder that is attached to your
scope rings or the scope tube. The flexible rope allows the shooter to
adjust for right or left hand use. The Data cards are two sided allowing for
up to 10 targets designations, distance, dope, and 2 wind holds.
Get them at Triad Tactical https://triadtactical.com/dope-rope-data-card-holder/