Well its a good all round barrel sock, is highly reliable and well built. The unique feature of it is that it has an elastic tipped end which is designed to catch paint in the event of a mis-fire. This is rather unreliable in its working, it seems to catch the paint only half the time. Of course if you happen to have a very sensitive trigger, 2 shots is going to cause 2 breaks. In all cases no paint ended up in or on the barrel, which is definitely a good thing. The adjustable strap means you can wrap the elastic cord around nearly any part of your marker, which is a bonus compared to inferior unadjustable straps.
Since it dosnt do (reliably) what its stated to do (with regards to the paint catching), it isnt perfect. One could consider the catching technology more of a bonus, since other barrel socks do not have this feature. For a barrel sock however, its definitely a good purchase.