Perhaps, it was due to its thinness, but this particular slide was not as well made as the other two Dunlop glass slides that I own. While the “flaws” (if I can even call them that) did not in any way impact the usability of the slide, it would still have been nice if the edges were a bit more even, without the slight dimple on one side and some warping on the other. Having paid this much for a simple glass tube, I expected a little better craftsmanship.