I bought this zipper to replace the one that failed on an expensive, serger sewing machine trolley. Because of the weight of what the trolley carries, it was crucial to have an extra sturdy double zipper. Two things especially are impressive: first, that the zipper is available in so many custom lengths to exactly match the dimensions of the case as there was no room for error and impossible to adjust.the trolley lid; and second, this zipper is beefy and while it functions like the one that failed, the Annie double slide zipper is impressively strong.
The pull glides easily in both directions, equally smooth turning corners as on the straight. The original, manufacturer-installed zipper failed at the corners, so in the past two months I've given this new one really hard use, testing it out and in daily use. I'm confident that this zipper will continue do the job, where the OEM zipper was sketchy from the beginning. I'm confident that the heavy-duty thread I used to sew the zipper into place will fail before the zipper itself. When this all started I was sure I'd have to replace a $200 trolley and Annie's zipper allowed me to repair it successfully--under ten dollars and better than new!