The 7s55 is an upscale version of this 7s35 caliber with a special-edition “Tokyo Stripes” rotor. This rotor features a striped look and a signature red font. Also, the movement has more polish and a better finish. The reason why the 7s55 is so rare and unheard of is that it was only used for one Seiko watch: the SLX-Series. This is a timepiece part of the “Seiko 5 Superior” collection, which is strange because it contradicts the aforementioned “day-date” rule of Seiko 5s. Oh well, I guess the “Superior” brand gets a pass. Consequently, the 7s55 is the shortest-lived caliber of the 7s family, and thus it’s also the rarest of the bunch. So, this is my rarest collection, I rarely use it, mostly keep in my storage box, unfortunately I lost manual books. There are minor signs of wears but it still look a new one and still keeping good time.