Unisex Waterproof Rain Boot Cover

What size will fit over a size 11 boot? I purchased a set of XL Tourmaster waterproof covers and they are way too small.

Description says "2 pack." does this mean there are two pairs (four boot covers), or one pair consisting of two boot covers?

Description says "2 pack." does this mean there are two pairs (four boot covers), or one pair consisting of two boot covers?

I wear a 11.5 boot, what size would I need?