The function of perpetual calendar is a highly complex mechanical mechanism, which has attracted numerous watch lovers. As one of the three complicated functions, perpetual calendar has always been connected with elegance. The other two are tourbillon and minute repeater. However, the complication usually means that it needs much more components. But now many perfect imitation watches have avoided the problems of the thickness.
Audemars Piguet Royal Oak

Although amounted with the complicated function, this Audemars Piguet Royal Oak copy watch with blue dial is ultra thin. The movement is especially designed for this ultra thin case which is only 6.3 mm, embodying the advanced technology of the Swiss watch brand.
IWC Pilot’s Watch

Thanks to large size of 46.5 mm IWC knockoff watch, the function of perpetual calendar could be set on the dial. You will not have worry about the readability. It also features the dark blue dial and matt black ceramic case.