I use the box MA120 MKII floor monitor for my drumset and I bought this together with the speaker. It does the job and after a few years of regular use the monitor actually looks pretty new, which is nice.
However, for this price it could be more thickly padded and easier to put on - the fit is tight, so it takes a bit of effort to slide it on after a gig.
PROS: custom-made for the Box MA120 MkII monitor, protects it from scratches in transport (but not from bumps/impacts).
CONS: price, too tight fit, lack of any padding.
On the whole, since the monitor has been very reliable and useful on many gigs, and it's nice to have it looking fresh, clean and unscratched (also helps resale value if I ever upgrade it), I would probably buy it again despite its shortcomings.