The Sidewinder DOPE Card holder is an awesome solution to keeping your ballistic data right where you can see it easily, and without having to come off the rifle! When those seconds count, see your data come ups or holds in an instant and get those shots! It has a flexible arm that allows for many positions, and can't be harmed by banging into trees or barricades and such. The Sidewinder attaches anywhere you like on the rifle with the supplied Velcro mounting option.
The Sidewinder comes supplied with ten blank data cards, and they are standard business card size as well. You can also just insert a white card and use a dry/wet erase marker on the clear film layer. It cleans up with alcohol or hand sanitizer.