just as it is on the description, appears to work well, but can't verify the accuracy of the power meter. be aware you need a tool to install the spider to the shimano crankset. something like TL-FC41 Direct Mount Chainring Installation Tool. You also need a shimano pre-tensioning tool - like Shimano TL-FC16 + bottom bracket tools and other workshop tools an supplies. Don't get this unless you can access the correct tools!