2++

2++ means that it still is a classic envelope design but one side is in 35 mm = 1 3/8" mesh and the other in 40 mm= 1 5/8" mesh .

You are free to choose which side you hang towards the wall and from which side your horse is supposed to eat. The 35 mm = 1 3/8" mesh is standard SlowFeeding mesh that work well for almost everything and the 40 mm= 1 5/8" mesh is for more coarse hay or straw.
Why choose, when you can have them both?