Brand new, Unit had been asset tagged but never used. The Martindale Proving Unit PD440 and Voltage Indicator VI13800 Set is designed for measuring low frequency AC/DC voltage. With a DC frequency range of 1-400Hz and a maximum voltage of 400v, this unit is ideal for proving the correct operation of your electrical installation. The set includes a carry case for easy transportation and storage, making it convenient for professionals to carry out voltage measurements on the go. The Martindale brand is known for producing high-quality electrical testing equipment, ensuring accurate and reliable results with this unit.