Product Description: There are 15 count pulse calculators on the two dials. ■Glow in the dark printing allows you to check even at night. Product Specifications: Chain length (including clip): Approx. 13.6 inches (345 mm) (included short chain length: Approx. 2.8 inches (70 mm)); Waterproof for everyday use; Comes with a second hand stop function in any position; Power supply: SR-626SW x 1 (with test battery); Size: φ1.2 x 0.3 inches (30 x 8 mm); Model number: EEPW10 mm).