Product itself is acceptable, but the terrible documentation doesn't help at all. Had to stick to another documentation, which is not even affiliated with the product, but does understand it more than the one, who made and documented this product. Shipping was very slow, and I didn't receive an answer wether the item was shipped at all after asking. You're better off buying Trinket m0.
Seen the YouTube video and thought for the price I'd give it a try at worst I'd have to uninstall it, glad i did works great boots the hekate bootloader off the SD enableing me switch what payload I autoboot on the fly useful because of all the great CFWs available.