The Rolex Datejust reference 16238 features a 36mm 18k yellow gold case, powered by the automatic chronometer-certified caliber 3135 movement. This specific model indicates a blue dial and a yellow gold bracelet, typically in a Jubilee style. Water resistance is rated at 100 meters. The "rivetti seriale 7206" might refer to a specific bracelet rivet style and serial number, but the general bracelet material is 18k yellow gold.