Sensitive activation areas and two adjustable wristbands. Excellent sound quality. Two volume levels. Quick Start instructions printed on activation area membrane. Compact, portable and sturdy. Dimensions: 3" x 1 5/8" x 3/4". Weight: 2.5 ounces. Four 1" (2.5cm) message activation areas. Up to 70 seconds of message space. Nickel-metal hydride batteries. Battery charger.