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 spring are easy to replace with the new ones provided.