At first glance the Sling Sleeve from Blue Force Gear may seem like a solution looking for a problem. Once you think about it, however, you might just see a reason for owning one - especially if you suffer from the tyranny of garrison conformity.
Since slings made of modern materials began to replace those of leather or canvas and certainly since the the advent of all the different "tactical slings" there have been arguments about how they should be used, if they should be used at all, what type to use. The arguments aren't surprising, really. Our community tends to debate virtually every TTP or piece of kit that comes available.
One common, borderline comical, sling-related matter I've seen argued about over the years is what to do with what's left over. It may sound silly, I know, but I'm betting a lot of you reading this have spent at least a few minutes rigging up some sort of field expedient way to fasten the floppy bits left hanging by some sling breeds once they're adjusted to where you want them.
As problems go, issues with snagging your sling in the armory, your gun safe, in a vehicle rack, etc. aren't exactly dire but they are a nuisance. Even if you're not trying to abide by the United States Ordnance Manual of 1861 (all slings will be manufactured of russet leather) there are lots of garrison issues of "sling management" becoming only slightly less catastrophic than egregious safety belt violations perpetrated by those desperadoes who PT in the evening in civilian clothing.
The Sling Sleeve is certainly a neater way to handle the floppy bits than wrapping them up in black electrical tape or wire, and far less likely to launch the First Sergeant or SMAJ into an apoplectic fit. They're a small, extremely inexpensive piece of kit recently released by Blue Force Gear to solve "sling management problems." Each one is a 5" long tube of elastic that will hold a sling neatly and snag free without impeding its deployment. The Sling Sleeve fits most 2- and 3-point slings including their Vickers Combat Application Slings.
I can almost guarantee some S4 somewhere will be directed to put one of these on every rifle in his units armory. You watch.