Get the right strap for your seiko as this company makes rubber straps specific to your seiko's geometry. Specifically, the straps are designed to leave no space between the spring bar and the case. They are in other words, specifically crafted for a specific seiko model. For example, I have a samurai, but mistakenly ordered the SKX strap.
Because of my error the strap sat maybe 1-2mm off the top of the case. As it stands, Blue Crater do not make a gray strap for the samurai. I suspect it's coming (fingers crossed).
Nonetheless, the strap is super high quality. And Blue Crater will certainly succeed by making these awesome straps for various seiko models. Are there cheaper straps? Sure. But buy nice or buy twice.
Or as the review that sold me on the strap says: this is the one you're looking for: high quality, affordable, and durable. I haven't worn a better rubber strap… now… if I can get a gray one for my samurai.