Heatilator is a full line fireplace manufacturer, actually a sister company of Heat-n-Glo and Quadrafire, all which are owned by HNI industries.
However, the term Heatilator is often misused as a generic term for a Heatform , which is a steel fireplace box built into a full masonry chimney.
This can be confusing as many of Heatilators current products are pre-fabs fireplaces with metal fireboxes and chimneys. This means they cannot use many fireplace inserts and must use special glass doors, etc.
However, Heatform fireplaces are classified as "generic" and can use most of the same accessories, stoves and inserts that fit regular masonry fireplaces.