Seiko Prospex has been teasing a new addition to its popular "Tortoise" collection for quite some time. Today, it finally unveiled two models in green and black ceramic that are the perfect combination of traditional and modern Seiko styles. The SRPB51 features a rugged case and light beige dial, while the SRPC49 features a more formal black dial with gold accents.

As you can see, the bezels and case backs of both watches are covered in a subtle pattern, giving them an elegant look that is also durable. Not only do they give off a unique vibe from other Prospex models, but their wide-ranging case diameter and extraordinary legibility also make them stand out.

Seiko's ceramic technology, including the case material itself, is of course a huge selling point here. In addition to its unique look and hardiness, I want to mention how light these are on the wrist. The SRPB51 weighs in at just over 140 grams while the SRPC49 is right around 125 grams. This may not seem like a big deal, but it is particularly noticeable when you place them next to other models in the Prospex and Grand Seiko lineups.

The dials of these new models also represent another first for Seiko. The SRPB51's dial features Japan's standard 60-minute indices that are coated with LumiBrite and applied to the surface of a white lacquer dial. The SRPB51's second hand is filled with LumiBrite, as well. The SRPC49 uses smaller indices that are set into the subdials at 3, 6, 9, and 12 o'clock.

Both watches come with a stainless steel bracelet that features solid end links and fold-over push buttons. Given their large diameter, these also wear very comfortably. Seiko is known for making handsome watches. However, it has always placed greater emphasis on legibility than design in its Prospex lineups. This time around, however, the brand created models that give off a unique vibe, thanks to their case material and dial designs.