Rosary bracelets are not common. A rosary is not a talisman, rather it is an aid to meditation. By tradition, there are three sets of mysteries (joyful, sorrowful, glorious). For a reference on rosaries may I suggest wikipedia.
A rosary bracelet consists of 10 beads ( one decade); a cross (crucifix), and a medal. Think of it as a condensed version of the rosary. Since it can be worn on the wrist, it is sometimes used to show devotion. It can be given as a “first communion” or confirmation gift. Although not a chaplet or pocket rosary, they may be kept in a purse or pocket.
The rosary bracelet shown consists of wonderful heart shaped millefiori beads. This bracelet has a magnetic clasp that makes it easy to wear. It is 8 1/4 inches long and weighs approximately 3/8 ounce. “Millefiori is a glasswork technique which produces distinctive decorative patterns on glassware.” (source wikipedia)