Based on my watches, 140mm is the perfect size for a 17 cm/6.75 in wrist, for watches with a lug-to-lug between 45-49 mm. 130mm is usable but can feel a little tight. For a lug-to-lug of 52mm, 140mm starts to feel a little too loose.
I just put it on my Uranus Moonswatch and the colour is just perfect! The OG strap was so bulky and uncomfortable. Putting this strap on made it so comfortable that it’s unnoticeable on the wrist. I didn’t realise but it has quick release function, making it easy to change straps around. Shipping fee was a bit steep, but it was quick. I would definitely order another one in another colour in the future. I can tell that the product is high quality like other Delugs products.
Fit is very subjective, so finding the right size with a one-piece elastic strap is more difficult than traditional straps. I followed the instructions on how to measure for the appropriate strap length for my watch. I came in at 128mm and rounded up to 130mm, which is what I ordered. But the elasticity in these straps are quite strong, and when I did slip it over my hand (which is very tight) and onto the wrist I found it to be too tight. I needed another 10mm in length for it to truly fit comfortably. I purchased 3 of these straps in one order. Add $60 for shipping and duty fees and this turns into an expensive experiment. If you like your straps super snug then go with their suggested formula to determine strap length. For a more comfortable fit, I would recommend adding 10mm to your final calculation.
Elastic Loop Light Blue/White