Multipurpose lockable enclosure for a wide range of larger size devices, components and instruments, such as keypads, annunciators and automated external defibrillators (AEDs) which require protection from vandalism, accidental damage, as well as the elements, such as dirt and grime. Spacers, integrated hinge and covers are formed from tough polycarbonate material. The polycarbonate enclosures are backed by a three year guarantee against breakage and damage in normal use. STI enclosure is lockable with either a thumb lock.