HP Model HP-01 rare calculator watch ref. 1801A from the 70s. Stainless steel, case no. 36084, quartz movement, in complete working order. Digital display for the time, calendar, alarm, chronograph and calculator with memory function, keypad for operating mathematical functions, numbers and letters for setting the various functions. Stainless steel link bracelet with folding clasp, suitable for a wrist circumference of approx. 18 cm. Used condition, visible signs of wear. Printed operating instructions and USB stick with manual enclosed. Diameter approx. 41 mm.