Below are more identification characteristics:

Cap:

Convex and becoming flat with age
Color is orange to a brilliant red-orange
Caps are pretty hefty, from a few inches in diameter to up to 6 (around 15 cm)
While the surface is mostly smooth, the edges are lightly striated
It's worth noting that, unlike some other Amanita species, this one does not usually have any warts or patches on the cap.
This mushroom displays light yellow "free gills", which means the gills on the underside of the cap are not attached to the stem. Whether gills are free or attached is often an important factor in mushroom identification so look closely!