Using this Topeak torque wrench is a breeze. First, to set the torque, simply pull and rotate the wrench to select your target torque value in the range of 2 - 10 Nm. When you're tightening a frame or component bolt, turn the ratchet wheel. Once the preset torque is reached, you'll hear an audible 'click' signal, which means you can stop tightening. The five - bit storage pen with a visible window is really handy. Just look through the window to quickly find the 3 / 4 / 5 Allen bits or T20 / T25 Torx® bits you need. After use, the storage pen integrated with the tool holder can snap to hold the Ratchet Stick together, making it easy to take with you when riding or for storage. As for maintenance, keep it clean and dry. Since the bits are made of S2 hardened steel and the ratchet of hardened steel, they're quite durable, but avoid using excessive force that might damage the tool. Also, the body made of aluminum and engineering - grade polymer can be wiped clean with a soft cloth. And always check the accuracy of the torque setting periodically, as it has an accuracy of +/- 4%.