The 411.NX.1170.RX is the 45 mm titanium Big Bang Unico. It is the version through which many buyers first come to know the Big Bang: a layered case with six H-shaped screws in the bezel, an openworked dial and a rubber strap. The titanium makes the watch lighter on the wrist than its size suggests.
Inside is the HUB1242, a version of Hublot's in-house Unico chronograph calibre. It is a self-winding movement with flyback function and date, with the column wheel visible on the dial side. The power reserve is about 72 hours, and the watch is water-resistant to 100 metres.
The same case and calibre also exist in black ceramic, as the Black Magic 411.CI.1170.RX.
On a pre-owned example we look for scratches and polishing marks on the case, because titanium shows wear sooner than steel, and at the condition of the H-screws and the intermediate layers. We test the chronograph, including the flyback, and assess the strap separately.
Finally, we compare reference and serial number with the guarantee card; what a complete set includes is explained in our guide to box and papers.