Richard Mille RM27-01, Rafael Nadal Grey Anthracite Polymer 47MM Watch RM27-01(PRE-OWNED)DESCRIPTION In 2013 Richard Mille set the world record for creating the lightest mechanical timepiece at 18. 8 grams when they released the RM27 01. To achieve this lightness the RM27 01 case is made of anthracite polymer which is injected with carbon nanotubes to protect the movement and tourbillon and hold tension. The anthracite color is due to the high concentration of nanotubes and it has a grilamid sapphire crystal. The case is tonneau shaped