With a Stabila Plate Level Maintenance Kit, you'll easily return your well-used Stabila plate level back to as-new working condition. This kit contains the parts needed to replace the old lock mechanism and nylon glides. You can maintain your plate level in only 10 minutes. Just remove the locking pin with the provided hex keys, then remove the locking mechanism and pull out the slide extension. The nylon bushings and tension springs are easy to replace with the new ones provided. Once the extension is back in place and you've installed the new locking mechanism, your plate level will be back to its optimal working condition. The quality nylon bushings in this replacement parts kit will keep the slide moving smoothly and will help maintain a tight fit when extended. We recommend installing a Stabila plate level maintenance kit once a year for plate levels you use daily.