These rollers can be supplied on request and have the same features of the series 135 and 138 but with a toothed belt head instead of pinion sprockets in the driven versions of 135 series and friction 138 series, (interchangeable). The toothed belt head is made of POM black colour, pitch 8 mm, Z20, for belt rings Polychain GT width 11,2 mm or similar, compatible with the corresponding HTD belts. It is important then to follow the belt manufacturers’ specifications for the transmission calculation, the rollers pitch and tolerance in relation with the eventual initial tension. We suggest contacting us in this case. The rollers have sendzimir zinc-plated tube (Z. exec.) or special anti-shock PVC (V exec.) with precision radial 6002-2RZ bearings.