Crafter Blue CB03 20mm Watch Strap Curved End Rubber Band Replacement for Seiko MM300 MarineMaster SBDX001, SBDX003, SBDX005, SBDX017, SBDX021(SLA019J1), SBDX025, SBDX023, SLA023J1(SLA021J1) etc

Switched out the bracelet and haven’t looked back. First off, the watch is way more comfortable with the rubber strap. The straps fitment is spot on - no play at all between the straps fitment and lug. The quality is great - rubber is thick and sturdy but still comfortable for everyday use. The appearance of the watch is what I would call sportier, which I’m keen to. Used the stock mm300 ratcheting clasp with no issues. The 6’oclock side of the rubber strap is fixed you adjust my shortening the 12’oclock strap. For ref my wrist is about 7inches and it fits perfect. Bought Ken for each of my mm300s

unfortunately I cut it to size before realizing that 2 of the holes are ripped, so cannot return. Otherwise it seem to be a nice band, just I can’t trust it with the material so brittle at the holes

Quality is good and fits my husbands watch perfectly

Love how it fits and makes the watch feel. Takes the top heavy aspect of the marinemaster and makes it very wearable.

When I tried to attach to my MM300 SLA021 the strap wouldn’t fit close enough to the watch to allow the spring bars to go into the holes in my watch. In other words, the strap could not be attached to my watch and kept falling off. So this strap needs to be revised for better fitment. When I googled I found this is a common problem with this product.

Wanted a rubber strap and still utilize Seiko clasp from the OEM bracelet. This thing looks, fits and feels great and easy to install. Need to buy the orange one now!

Good quality and material and nice feeling on the wrist. My one and only complain that unfortunately kills the whole experience is the length. The short side of the band is too short so someone with a big wrist like me (8.25”) that will use full length, always has the clasp sideways. That could have been avoided if the short side was little longer, making the band easier to size

I like how well this strap is designed. It fits the MM300 perfectly. How well it looks and works with the MM300 clasp is just great. 100% satisfied with this purchase.