--- type: restriction id: usps-audible-fire-alarm-systems-powered-by-compressed-gas asset: shipping-restrictions-by-class title: "Audible fire alarm systems powered by compressed gas — Postal shipping restrictions by item category" sources: - https://pe.usps.com/text/pub52/pub52c3_021.htm source_quote: "Audible Fire Alarm Systems: These systems, if powered by compressed gas, are acceptable in domestic mail via surface transportation if they comply with conditions in Packaging Instruction 2E" generated: true harvested: 2026-08-04 stale_after: 2027-08-04 item_category: "Audible fire alarm systems powered by compressed gas" carrier: "USPS" restriction_type: "restricted" scope: "domestic mail via surface transportation" conditions: "Acceptable via surface transportation if comply with conditions in Packaging Instruction 2E" verified: false unverified_fields: carrier, item_category --- **Item category:** Audible fire alarm systems powered by compressed gas **Carrier:** USPS **Restriction type:** restricted **Scope:** domestic mail via surface transportation **Conditions:** Acceptable via surface transportation if comply with conditions in Packaging Instruction 2E > Audible Fire Alarm Systems: These systems, if powered by compressed gas, are acceptable in domestic mail via surface transportation if they comply with conditions in Packaging Instruction 2E Source: