DIY tools for residents. Not for trade use. Suitable for DIY trial before hiring a plumber. Any regular home drill will do, cord or cordless. Suitable for sink, drain, stormwater, or tub pipe. Black Spring: The success depends on: the strength of the drill, the length of the cable, how curved the cable is, root cause of the blockage, and user skill. It takes lots of time and patience. Black Spring: Comes with different drill bits to treat difference blockage. You can use the coil bit to extract samples to determine root of the cause. You can sharpen the bits to improve cutting. Black Spring: Easy to bend at the near position but difficult to do so at the far end. Shorter cable gives a better chance. Easy to penetrate soft materials in the pipe, but difficult to penetrate sand or stone Soft Spring (chrome color): soft, flexible and not extendable. Specially designed for lighter blockage, short distance cleaning and curved pipe for toilet, sink, tub, etc. Read user manual and its warning message to avoid any issues. Suggested to operate by 2 persons with great patience. With this electric drill driven drain auger, you can do it yourself to unblock the sewer pipes. No special technique required. No training needed, no license needed. The black spring is designed for storm water and longer distance cleaning. It can also be used for toilet or small drain pipes as long as it can enter from the exit. The soft spring is usually in chrome or bronze color, and is mainly used for cleaning of sink, toilet, or shower. It is much more flexible than the blackspring. BLACK SPRING: Passing through curves or U trap is difficult at the far end, but easy on the near end, while the soft spring (2.5m) is more suitable in this case. You can always connect the springs together to make it as long as 24 meter in overall length. Note, the additional 2.5m soft spring can't be connected and extended to the black spring. It is suggested to use alone with the shank adapter only. This product comes with changeable drill bits, which has 6 different types with different functions.