Slightly more difficult to use than in the videos, leaning something heavy against the back plate helps to keep it from moving. Despite this, it is still very easy to use. The struts secure the plate to the rim rather than the uneven tire, and with some care in placement, they make it easier to center the plate on the tire. Both contribute to accuracy and reproducibility. The included chart makes converting your reading to degrees very easy. I felt the need to run a deburring wheel around the edges, most won't be that picky. I bought them with a separate 1100p caster/drop sensor; If you do more, consider an all-in-one cymbal set. The 1100p makes it easier to be accurate as it has three contact points so you don't have to worry about holding the tool perpendicular to the rim, but it's also more expensive and another bulky tool to keep. Both versions have a built in wheel angle indicator that is extremely easy to use and makes measuring caster surprisingly easy.