These drills are very well made and come in a nice carrying case. The design of the case makes it easy to insert bits (insert at an angle to the base of the holder, and then push the tip into the groove). All larger bits have an anti-slip notch, which is a nice feature. Works great with metal (aluminum, steel, stainless steel - all with no problems). Wood is fine too. However, on thin plastic or thin wood, especially plastic, the bit bites too hard and can sometimes leave a messy hole. It's fine on metal. With careful control of pressure and drilling speed, there are no problems with any material. With slow/medium drilling speed and very light pressure, the plastic holes are nice. In addition, the sleeve and bits have already undergone a significant treatment and the finish has not deteriorated. It is nice that the lettering is far below the shaft, which reduces wear.