The code 561.0016.3 is the official reference number (Reference Number) this model is the ladies version of the iconic Rado DiaStar series. The technical characteristics and details for this reference include: Size / Case: It has more refined and small dimensions (diameter approximately 28mm), designed specifically for a woman's wrist, while maintaining the classic oval "shield" shape. Mechanism: It is an automatic mechanism (Mechanical Automatic), which means that it winds itself with the movement of the hand and does not need a battery. Dial: It has a gold dial with diamond indications (Diamond) and a date window (Date) at the 3 o'clock position. Materials: The top is made of Rado's traditional hardmetal with a gold coating, while the bracelet is gold-plated steel.