Dock Seals and Dock Shelters are both ways to help protect your building's environment and prevent drafts. They both create seal, stop drafts, and keep debris from enter the dock, so which one do you need? While your best bet is to talk to a Cisco Salesperson to receive knowledgble counsel, we will try to summarize.
A dock seal is mounted around the dock door to create seal between the dock and the trailer exhaust fumes from entering your building. The truck backs up, and the trailer presses tightly against the seal.
A dock shelter is also mounted around the dock door, but surrounds the trailer that backs in. The seals inside the shelter surround the trailer to provide the seal.
Left, the truck rests against the seal. Right, the truck is inside the shelter.
Price: Seal is usually cheaper.
Application: Shelters are better for larger doors
Durability: Shelters experience less direct damage.
No matter what, you want to find the best solution for your application, and the best way to do that is to call the professionals at Cisco.