The Seiko 5 “Bottlecap” gets its’ nickname from the bottlecap shaped case it has, which is quite obvious. The solid 316L stainless steel case sits at a diameter of 45MM...but really wears like a 40-41MM watch when strapped to the wrist. I was actually quite impressed by the smooth brushed finishing Seiko did here, which honestly is equal to some of their more expensive Seiko Prospex models in terms of quality and refinement. Anyway, the thickness is roughly 13MM and we get nice drilled lug holes which is really nice to have on a modern watch. ( 22MM lug width ). As most seiko 5 sports models are water resistant, the bottlecap is no different and has a 10 ATM ( 100M ) rating. This piece is definitely safe to swim with or go snorkeling if your into that. If we flip the watch over, there is a nice exhibition window displaying the automatic Seiko movement...which is quite bland and not really necessary in my opinion.
The glossy black dial really pops on this model and features XL applied lumed markers with silver outlining. It is your typical dive watch layout, or shall we call it “Seikomariner” layout. The long sword hands are easy to read at a glance as is the long needle seconds hand, reaching to the end of the dial. One nice detail is tje red “Sports” print below 12;00 , adding some flavor to the dial. The crystal utilized here is a hardened mineral crystal, which is sort of expected at this $180 price.
Powering this piece is the well known in-house Seiko automatic 4R36 Day/Date movement. This is a trusted and reliable one which contains 24 Jewels, Hacking, Hand-Winding, and a 3 HZ Beat rate. These movements are widely used in the Seiko Prospex range as well as the Seiko 5 range.
To be quite frank, the bracelet is not amazing. It is certainly not a throw away accessory, but it could be better. It has rather square shaped links, instead of curved links - making it feel a bit blocky on wrist. There is also no end links, so it sort of looks awkward with that gap at the lugs. I found myself experimenting with numerous NATO straps which really look great on this piece. It is most definitely a “Strap Monster”.
Furthermore, I really enjoy the peculiar aesthetic this model has to offer. I love the shape of the case and how it really does not mimic any other watches out there. It contains a decent movement, great lume, and 100M of water resistance all at a price below $200. Can you really ask for more from Seiko?
The main component of a mechanical movement is the mainspring, a spring that gradually unwinds and transmits energy. A mechanical watch will keep accurate time despite requiring winding up if it's manual. ... Inside an automatic watch sits a small weighted rotor that has to oscillate in order to wind the mainspring.