Large display that is easy to see even when worn on the waist (15 mm character height) Single function that is easy to use even for beginners and silver layers. Sensitivity adjustment function makes the battery lid easy to fall off and reduces the risk of accidental ingestion. Specifications: Model: PD-645 [Temperature range] 0°C - 40°C[Battery life] Approx. 2 years (when using 4 hours per day) Power supply. DC3V (CR2032 lithium coin shape battery x 1); Main accessories: Instruction manual (English language not guaranteed), trial battery (CR2032 coin shape lithium battery x 1; Main material: ABS; Product dimensions: Width 2.6 inches (65 mm) x Height 1.5 inches (37 mm) x Depth 1.1 inches (28 mm); Product weight: Approx. 1.1 oz (30 g) (including battery).