Choose our Service Door when you need an interior or exterior closure option that is secure, durable, customizable and compact. We didnt invent the insulated door but we perfected it. Choose our market-leading energy-efficient insulated doors in extreme environments or anywhere you want to save on energy costs and go green. Side Folding Doors and Grilles. Easily and quickly transform a large room into two or more sections for security, privacy or unpa.