The Magpul Dynamics Precision Rifle Data Book uses a simplified density altitude-based, color-coded chart to record your rifles' data across a wide spectrum of shooting conditions. Using a rugged, all weather material that can be written on using map pens, pencils, and non-permanent markers, this data book was designed to perform in austere conditions. Recorded data can also be erased with alcohol based substances, returning the material to its original state. All pages are reusable and include a field expedient density altitude calculator, cold bore shot tracking log, known distance data confirmation pages, range cards, a point of impact shift tracker, and simple hasty hold formulas. Ring not included. Features True all-weather, semi rigid writing surface Recorded material is erasable with alcohol Field Expedient Density Altitude calculator Cold Bore/Night Optic and POI Shift Track Logs KD Data collection sheets from -5000 to 16,700 feet DA Field Range Cards and Unknown Distance/Observation Amplifying Remarks Cards Moving target and Hasty Hold formulas 7.0" H x 5.0" W Made in U.S.A.