Available in both 110/120 and 220/240 volt versions the Solo 423 and 424 are the professionals' choice where cables and leads are acceptable. The Solo 423 corded heat detector tester is lightweight, simple to use, and features a universal design to suit a wide range of detectors. This detector tester is suitable for fixed temperature, rate-of-rise, and combination detectors up to 194°F / 90°C. Additionally, the Solo 423 features some of the quickest detector activation times and includes a 16-foot cable for an additional range of motion.