The U.S. Army is seeking information on commercially available external rucksack frames and suspension systems that are compatible with the standard MOLLE 4000 Rucksack and capable of supporting a 120-pound load. The required performance testing includes specific drop tests and airdrop slide impact tests at ambient and extreme cold temperatures, as well as human factors testing with combat loads. This is a Sources Sought notice for planning purposes only, is not a solicitation, and no funding or commitment to procure is currently available. The place of performance for any future testing or contract would be Natick, MA. Responses, which are voluntary and at no cost to the government, are due by 6 February 2026 and must include detailed product and company information.