The STM Right Angle Bevel Gearbox ZL Series from HMA Flow & Industrial consists of right-angle gearboxes that are silent-running, and designed specifically for light-duty applications. The range features a single-piece aluminium body, Gleason gears, and overrated bearings. The backlash is 15′ to 30′ (minutes).

All gearboxes are supplied filled with lubricant for all mounting positions. Three mounting flange types are available. Depending on the size, there are three or four mounting-through holes on the body itself. Both a two- or three-shaft design is available, with ratios of 1:1, 2:1 or 3:1 available for all sizes.