Vesda VPS-220-STX5-SLV Power SupplyVESDA E Power Supply Units are uniquely designed to complement the style and appearance of VESDA E aspirating smoke detectors (ASDs) and are technically matched to provide sufficient current and battery charging capacity to meet the requirement of EN 54 4. The STX variants are VdS certified and CE marked to EN54 4 so are particularly suitable for use in territories where these approvals are required.