Zeitgeist 1. All 4.2" (107mm) diameter motor can be fitted right away from the box, without need of reducing collar. In this range are usually 3-1/4 HP motors. And it's a perfect match with our heavy duty ... 1. All 4.2" (107mm) diameter motor can be fitted right away from the box, without need of reducing collar. In this range are usually 3-1/4 HP motors. And it's a perfect match with our heavy duty 3-1/4HP router motor. 2. All 3-1/2" (88.9mm) diameter motors. 3. All 80mm diamter motors, like: most of the CNC spindle moulders on the market. 4. All 69mm diameter motors, like: DW DWP611, DW DCW600. 5. All 65mm diameter motors, like: Makita 700C. Toon meer