Installation and maintenance of computer hardware, computer peripherals, smart card readers, and radio signal receivers for electronic payment; installation, maintenance and repair of apparatus and instruments for controlling and rescue, namely, automatic discharge systems for fire protection, electronic protection equipment, namely, intrusion detection equipment, environmental detection equipment, fire alarm and detection equipment, alarm central stations, and monitoring central stations, namely, audio and video transmission, recording and playback equipment; installation, maintenance and repair of equipment for monitoring fire suppression substance discharge systems and waterflow alarms; installation, maintenance and repair of anti-theft and break-in alarm equipment; installation, maintenance and repair of strong-room alarm equipment; installation, maintenance, repair of motion sensing equipment; installation, maintenance and repair of electronic network equipment; installation, maintenance and repair of electronic communication equipment; installation, maintenance and repair of nurse call systems; installation, maintenance, repair of message programming equipment; and installation, maintenance and repair of electronic locking systems