1. Arcuate bevel-gear instead of worm gear is adopted，with high efficiency and saving over 20% electric energy than traditional models.
2. Arcuate bevel-gear is made of chromium-manageanese-tianium with carbontitriding on the surface.Long life span and high rigidity are available.
3. Mechanical seal is available to against oil leak pollution.
4. Protector inside is available to avoid motor bening burnt accidentally.
5. PE float，nylon impeller，stainless steel shaft and frame are available.