The Raymond Weil caliber RW 4280 (often written as RW4280 with no space) is a Sellita SW280-1 automatic moonphase movement used in Raymond Weil Masetro Moon Phase watches.
The text on the rotor reads: RAYMOND WEIL / GENEVE / SWISS MADE / CAL.RW 4280 / TWENTY-SIX 26 JEWELS
From the official instruction manual:
“Your RAYMOND WEIL watch was hand-assembled by our master watch- makers according to the most rigorous quality standards of the Swiss watch industry.”
What grade is it?
The calibre RW4280 appears to be a standard grade movement with Incabloc anti-shock system and custom Raymond Weil branding printed on the rotor.
The reason why “it appears to be” is because the brand does not mention the grade, and does not provide potential customers with clear/accurate images of what they are buying.
There are four variations of the Maestro Moon Phase. On one of the official Raymond Weil product pages for the model, a blurry low-quality image of the caseback is presented, making it difficult to see the details of the movement (source)…
On the 2 rose gold tone product pages, the caseback images are a little clearer, allowing you to see that it is not an actual picture of the model for sale. Look closely and see that they are using an image of a watch powered by “CAL.RW 4200” non-moonphase (source).
Editor’s Rant: It’s hard to believe that a luxury watch brand can manage to design and build a mechanical watch in a factory but not a website on a computer. Even if they were being cheap and didn’t want to pay for a photoshoot of the Moon Phase model, or they were waiting for a session with a photographer, it wouldn’t take much effort to simply edit the correct number on the rotor to be aligned with the contents of the description. We’re talking about items that cost $1,595 to $1,895 USD – surely the microbrand community would not tolerate such presentation of $500 and under watches.
And finally, on the blue dial steel model, there is no caseback picture at all (source).
Sellita claims that the power reserve of the caliber SW280-1 is 41 hours, but Raymond Weil lists a power reserve of 38 hours. It’s likely that the brand either carried that information over from their SW200-1 based movement specs, or they are just being conservative on the PR rating.