Richard Mille RM56- 02

Richard Mille caused something of a sensation when he pulled the wraps of the RM56 - 02 at the Hong-Kong Watches and Wonders exhibition in 2015.   Its remarhable "USP" being that it featured in
an entirely transparent case made from sapphire crystal.  Each case is said to have taken 40 days to cut, grind and mill from blocks of solid sapphire, with the sapphire bridge building the tourbillion moxement taking an additional 400 hours to make.

The base plate meanwhile, was hewn from titanium and suspended within the case by a remarkable system of 10 micro pulleys that tension the mechanism with a length of braided cable measuring just 0.35mm thick.

Due to the completely involved in making the watch - which uses the same, highly shockproof movement found in the RM27 - 01 Rafael Nadal model - a mere 10 examples were created, each one being supplied on a strap that appears to be a Swatch-like plastic affair but which is actually made from
a material called Aerospace Nano which is elastic, soft, waterproof and, importantly transparent.

All of the above, combined with the fact that we're taking about a Richard Mille watch, will have by nowlead you to conclude that this is not a cheap watch to buy new. 

Although everything is as they say, relative.