The patented design of this highly durable bag features 2-inch openings on all four sides; it’s made of heavy-duty 1200D nylon and reinforced with 211 cross stitches to stand up to your horse’s strong teeth. A Velcro top closure keeps her from eating out of the top of the bag and the two heavy-duty bull snaps on the adjustable hanging straps can be clipped to D-rings on both sides of the bag to also help seal off the top. An adjustable bottom strap with bull snap is also included to further stabilize the bag if needed. Derby Originals is the first company in the USA to offer a 1-year warranty on this hay bag. 4 sided patented design U.S. Patent No. D742 078.