The sapphire crystal with anti-reflective coating protects the black matte dial which contrasts well with the indices. The indices are not applied but have a generous layer of SuperLuminova lume. The four anchor Arabic numerals on the quarter hours allow for a quick read of the time. The hands also play well against the matte black dial providing excellent contrast: it's one of the reasons this design has worked so well in cockpits around the world.

The Sinn 556A is powered by a reliable ETA 2624-2 equipped with a golden oscillating weight which you can admire through the transparent caseback that is also made of sapphire crystal and A-R coated. In terms of waterproofness this little beast it rated at 200m (20ATM). 

The case is entirely brushed, meaning scratches will be less apparent: one more reason for which this is a great everyday watch!

The date window on the Sinn 556A is present at 4 o'clock. We find it remarkably well executed: unlike most 4 o'clock date windows, this one is horizontally displayed. It is very discrete, keeping the visual balance of the dial while still being there when needed. Sinn really did a great job here.

To conclude, the Sinn 556A offers a great mix of performance, durability and classic Sinn design. Although it's not cheap at a price in the range of $1150, this watch definitely has a great personality and can definitely follow you in your next adventure.