Sources Sought Notice for EXPANDABLE RIGID WALL SHELTER. DEPT OF DEFENSE - DEPT OF THE ARMY is seeking information for the production of One-Side Expandable ISO Shelter and Modular Extendable Rigid Wall Shelter (MERWS). These shelters are used for various purposes and have completed required testing requirements. The notice is for market research purposes only and does not encourage questions or guarantee a solicitation or contract award. Interested parties can download the notice, fill in requested information, and email it to Sara Rice.