over 3 years' testing on cutting machine, then we started to promote this gearbox. Gearbox all look same each other, but after one or two years working, some would start to get problem, but the good one still work same...There're quite many gearbox on market for CNC cutting machine, but after years' practice, we got this gearbox.....no problem after 3 years' sale.This gearbox is mainly for ...