These OEM belts seemed expensive to me so I took a chance and ordered a pack of 10 replacement Eureka round belts (https://smile.amazon.com/dp/ B013JKGOH0) . Even though they weren't stated to be compatible with my Koblenz, they fit perfectly and are just as good as the original straps. At less than a dollar each, they were a lot cheaper than those original belts.
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