I have used this with my canteen (which I also bought from USC) and I have no complaints quality-wise. My only problem is the ACU I ordered it in is a bit faded.
Nice covers but some problems
The canteen covers are very nice USA made ones. Only issues is that the OD ones are more like foliage and the khaki ones are coyote brown/tan and not as light as in the photo much to my disappointment. The OD and black ones tend to be a little shiny for some reason.
There is a quality control problem with the little velcro pouch for the purification tablets as a lot of the time, it's sewn wrong or completely missed, had to return several of these because of defects with the velcro pouch.
Other than that GREAT canteen covers.