Instructables
Picture of Ranger Bead Counter  Shoulder Strap
This is a idea to a ranger Bead Counter attached to my maxpedition Sitka shoulder strap, but can be attached any backpack, also glows in the dark you can find the beads in amazon. The bead Counter it's a military sistemas to keep the trak of the distance walked, every bead you pull it down every 60 steps with your left foot it can change between the different people heigh and walking habits. Every bead symbolizes 100 meters in the row with nine when you have pulled the nine you push up this one's and pull down one of the row with 4 when you have pulled all you have traveled 5 kilometers, use a distance you know to calibrate the amount of steps