※ Please carefully measure the ring size of your guide. If the size is different, it cannot be installed. If you can confirm the guide's model number, you will know the required size. These are SIC rings. Please use them to repair broken guides. They can be installed on guides with a frame ring contact surface diameter of 5.5mm. Here's how to install them: 1. Prepare the guide frame. The ring contact surface of the frame should be pre-sanded and cleaned. 2. As shown in the third photo, place the ring vertically and try to see if the ring can pass through to the other side. It's ideal if it goes through with a little pressure. If it doesn't go through, use a rod file to sand the frame and widen the contact surface. 3. Insert the ring into the frame. If it's tight, use protected pliers to gently crush and insert it (photo 4). 4. Apply adhesive to the border between the ring and the frame. Epoxy adhesive, which allows time for adjustment, is more suitable than instant adhesive. Apply adhesive to the tip of a needle or toothpick, and trace the outer circumference of the ring, applying it to both the back and front surfaces. A thin layer of adhesive is sufficient. Be careful as the ring can break if it receives a strong impact. When it breaks, it breaks easily with a crack, so be careful when inserting it with pliers. There are 3 pieces in a set in case of failure. Although the adhesive strength will be lower, it is also an option to sand the frame more and insert it loosely. If you use epoxy adhesive, it is unlikely to come off, so you don't have to be too perfect. If you do it well, you can convert inexpensive guides to SiC guides. If you are interested, please give it a try. This is a special item, so please ask if you have any questions.