Two comments:
Most units out there in the market are counterfeits, like the one you show in the picture. The main issue here is that instead of a 40A triac they may have triac with a much lower capacity, which can be dangerous in some cases. Make sure you get a genuine one. Try contacting your local distributor, not Amazon and the likes.
According to Fotek specs, you need 4V to turn them on, although I have succeeded with a counterfeit copy with a little less. This could be an issue, and you might require a (transistor) driver.
Otherwise, they are a good choice.