Hioki DT4200 [DT4221] True-RMS Pocket-Sized Digital Multimeter, 600V AC/DC with Voltage Measurements Only. The Hioki DT4200 Digital Multimeter Series consist of a complete lineup of 9 models ranging from professional to industrial to pocket meters, delivering a super fast response rate and safety features that take electrical testing to a higher level. The DT4221 is a pocket-sized digital multimeter designed specifically for electrical work requiring optimal safety, with ±0.5% DC V accuracy and wide 40Hz to 1kHz AC V bandwidth.