Uploaded July 2021 | Updated September 2026, 6 days ago

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SLE (Servo large envelope) machine. With an adjustable servo motor, this machine delivers speeds of up to 500 envelopes per minute. The stored information can be recalled for repeat orders creating reliable and consistent envelope production.
America’s Mailing Industry virtual exhibition:
https://postalmuseum.si.edu/exhibition/america’s-mailing-industry