Free rollers used to transport average and heavy loads in indoor and outdoor areas, which may be normal, dusty and/or humid. The housing of the bearings is calibrated ISO M7 and welded to the end part of the pipe, forming a monolithic structure (UNIBLOC). The permanently lubricated ball bearings used for the MPS series are 6202-type radial rigid bearings of the best brands and oblique type for the M series. Airtight protection of the bearings is guaranteed by the MECA sealing, which consists of a double acting radial labyrinth within a galvanised sheet metal cover, and an internal bottom plate that has a large grease chamber. The calibrated and drawn steel axle is perforated and threaded to be fastened with screws when the standard installation is implemented; alternatively, it is equipped with sockets at each end to be fastened with a spanner (17/14). Generally, these can be used within a temperature range of –20 °C to +100 °C. Sturdiness, equilibrium, reliability and minimum resistance to adjustment are distinctive features of these rollers..