The worm housings are supplied with centre fixation as a mounting aid. Gear shells shall be riveted. Please check whether the hole rod in which the gear is intercepted is still usable. If it is worn out, the gear can no longer handle it properly and move reliably. International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions., Manufacturer: Roto