18K, Bahne Bonniksen "Non-Magnetic" No. 62873 Pocket Chronometer with 52 1/2-minute Karrusel Regulator, c. 1897, white enamel radial roman numeral dial with outer minute track, sunk subsidiary seconds, blued-steel spade hands, three-quarter-plate, 15-jewel movement with going barrel, pointed tooth lateral lever escapement, cut bimetallic balance with gold timing screws, palladium balance spring with terminal curve, index regulation, ruby endstone, Bonniksen 52 1/2-minute Karrusel regulator, stamped with the Bahne Bonniksen patent mark on the pillar plate, movement and case marked "62873," dia. 55 mm.