Complying with EN 54 Part 11, the ZP785-3 is suitable for installations meeting the recommendations of many local codes (e.g. BS5839 Part 1). The unit is operated either by pressing a resettable element (EN54 Part 11) or by breaking a frangible glass with finger pressure. Glass elements have clear vinyl coatings on the front surface to prevent operator injury and to inhibit the release of loose fragments as the glass is broken. Both operating elements are easily interchangeable.