Fits pack well and secure around edges. Haven't had turely bad rain storm as of yet, so unable to rated keep pack dry.

I bought 2 of these in the grey color, one size small and the other size large.

Pros: Very light weight out of box. Gromet reinforced area toward the bottom that exposes the shock cord which makes it possible to feed through pack belt for wind resistance.

Cons: More expensive than some others. Seams are not sealed, which makes them useless out of the box.

Summary: No seam sealing is why they're so light weight. After seam sealing, the small weighs 3.6 oz after also removing all tabs and labels. Also after replacing drawcord and lock on stuffsack with much lighter ones. That's an addition of 1 full oz for the small. The large with all of the above modifications weighs 4.6 oz which is 1.3 oz heavier.

If you're looking for sealed seams and funtionality out of the box, I'd suggest that you consider other covers. After all, now they weigh as much as nearly any other.

Silcoat Pack Covers has kept both my wife's and my backpack dry on numerous Montana outings, but proved totally ineffective when we got slammed by an all day storm on the Olympic Peninsula Coast. I suggest that the Pacific NW requires heavier, more waterproof gear overall.

Very nice and light, plus it secures well around the pack but it has no taped seams!!! I sealed mine... we will see how well it works.