MPP300 is an optional accessory which allows measuring and recording the main parameters which characterize single- and threephase, single. and multi-string photovoltaic systems (up to three MPPT). Provided with a practical rigid anti-shock case, thanks to its lightness and its reduced size is the ideal solution for on-site use. MPP300 interfaces with SOLAR300N and SOLAR I-V for its settings, to start/stop recording electric and environmental parameters and to allow for the download of the recorded values. The master devices SOLAR300N or SOLAR I-V are only used in the initial and final phase of recording, and they do not play any active role while recording electrical and environmental parameters. Remote unit SOLAR02 (wirelessly synchronized with MPP300) is positioned next to the photovoltaic modules to measure environmental parameters (irradiation and temperature). Thanks to this synchronization, it is not necessary to place long connection cables between the environmental feelers and the device (cables which would impair the operator’s movements) nor to use a wireless connection between the environmental feelers and the device, what is generally impossible due to the attenuation of the signal caused by the presence of floors, reinforced concrete or metal structures.