That's damn expensive...I wonder if there's a happy medium like 5mm or 6mm that's tougher then 4mm but not as much money as 7mm. I'll have to measure my current silo's. They might even be 3mm. There's a few heads up decoys that the head has bent on the neck, but if I would have made a more "active" type heads up with shorter fatter necks they would be fine. Definitely not super durable, but I got the coroplast for free so I can't complain. What type of coroplast are the dive bombs made with? I've been looking at those decoys for awhile now but I've never seen one in person. Are they super tough material? The price is definitely right on them and I wouldn't mind picking up 5 dozen if they are durable.