True Uniform | GSA Schedule 541613 & SIN 339940 Supplier by TrueUniform Published: April 24, 2026 (6 days ago) Category Shopping Link GSA Schedule 541613 True Uniform simplifies federal procurement through GSA Schedule 541613. Offering a comprehensive catalog of SIN 339940 office supplies and branded communications, we ensure 100% compliance and streamlined acquisition for federal contract officers.