It's one of the more minimalist holsters on the market in terms of protection, as the EVO's corners are the only parts that are covered (other holsters cover some of the sides) and the spring clip appears to be doing most of the work of keeping the device in place. It also isn't shown to be compatible with any kind of case. This doesn't necessarily mean that a very thin silicone skin wouldn't fit, but I would think that Amzer would show it if it did.
The interior is lined with velvet, and the EVO's bottom ports remain accessible for charging/syncing/etc. without having to be removed from the holster.
Not bad for $16.95![Amzer]