※ Please carefully measure the ring size of your guide. If the size is different, you will not be able to install it. If you can confirm the guide's model number, you will know the required size. We are selling rings in 4mm, 5mm, 5.5mm, 6mm, 7mm, 8mm, 10mm, and 12mm sizes, so if you are looking for a different size, please search from the list of our products. 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 8mm. 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 passes through to the other side. It's ideal if it goes through with a little push. If it doesn't go through, use a file to sand the frame and widen the contact surface. 3. Insert the ring into the frame. If it's tight, gently crush it with protected pliers and insert it. (Photo 4) 4. Apply adhesive to the border between the ring and the frame. Epoxy adhesive with a time allowance 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 may break if it receives a strong impact. When it breaks, it breaks cleanly with a crack, so be careful when inserting it with pliers. It comes in a set of 3 for when you fail. 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 won't come off easily, 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.