※ 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 model number of the guide, 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 4mm diameter ring contact surface on the frame. Here's how to install them: 1. Prepare the guide frame. Sand and clean the ring contact surface of the frame beforehand. 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 shave the frame and widen the contact surface. 3. Insert the ring into the frame. If it's tight, use protected pliers to gently crush it and insert it. (Photo 4) 4. Apply adhesive to the border between the ring and the frame. Epoxy adhesive, which has a time allowance, is more suitable than instant adhesive. Apply the 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. It's okay if the adhesive is applied thinly. Be careful as the ring may break if it receives a strong impact. When it breaks, it breaks easily 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 shave 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 try it. This is a special item, so please ask if you have any questions.