Majestic Ally 2”x2” Holes Slow Feed 40” Very Sturdy Hay Net with Bottom Ring for Horses, Adjustable Travel Feeder for Trailer, Stall (Black)

Can't really speak to the durability yet, but they seem perfect so far. Holes are big enough that the horses can actually eat but small enough that the hay doesn't fall everywhere and get wasted. Flexible and easy to fill, holds 4 or 5 flakes easily.