K&M Pre manufactures miters (gutter corners) for easy Commercial Box Gutter installations. All miters are laser cut and riveted together as per specified angle. These items do not come pre sealed as straight seams connecting to gutters need to be sealed upon installation. This type of miter (mitre) is known as a "box miter" and that's because of its shape, which is different than a strip miter. Item needs to be secured with rivets, zip screws and / or soldered (recommended). A 45° miter is commonly known as a bay miter (for bay windows), however, not all bay windows share the same angles. A 90° miter is the most commonly purchased item. Custom colors, sizes, angles and materials may be available as custom items. Please, contact us for a quote.