Sizing - when choosing your size, this is the size of the bracelet not your wrist. Measure your wrist and add 1/2 inch for a tight fit or 1 inch for a comfortable fit or 1.5 inch for a loose fit. NOTE: These Beads are designed to slide effortlessly - for tight bead fit or for use in Water see our ungutted models Accidentally get your size wrong, no problem, we will exchange for you. Pace counters or ranger beads are manual counting tools used to keep track of distance traveled through a pace count. Made of 13 or more beads on a length of cord that are divided into two sections, separated by a knot. 9 beads are used in the lower section, and 4 or more beads are used in the upper section. This system was originally developed by our military. There are two ways to use the beads. One represents the paces you have walked, while the other is the distance walked. Getting your pace count: Measure out 100 meters Walk the entire 100 meters while counting every time your left foot touches the ground Use your typical stride and pace or your later count will be off Using the Beads Each of the bottom beads equals 100 meters traveled Each of the top beads represents a kilometer traveled While using your pace count, every time you have traveled 100 meters, slide one bead from the bottom section down Once you have used all 9 beads from the bottom section, you will then slide one of the top 4 down after you have traveled another 100 meters. This means you have traveled 1 kilometer. Separator is adjustable and can be moved up or down depending on your preference. Need more or less beads for your counting needs? Or need a different configuration? ;message us before purchase, we can customize.