I wanted an easy-to-use bicycle computer with cable connection, which requires not unnecessary batteries for a radio link. These are sources of error, which need not be. Ordering and delivery very good, unpacked, assembled, all without problems. Once the wheel circumference could not be taken directly from a table (tire 28 * 2.0), I have measured out very practical under load. On valve marking, valve exactly perpendicular to the ground, there chalk line on the floor, then forwards under load with the correct tire pressure, then after one revolution back chalk line on the ground under the valve. This method is simple and accurate. During operation, the small computer has been very successful, it has the most important functions easy to read as speed, plug, travel time and clock, what more could you ask for so little money. Strong buy recommendation from me