I got the ones from EastMall.net They are pretty flat.... whistle tip. The others I have seen at HealthCabin or whatever are like squared off round carts. The ones from EastMall is much flatter. They hold about the same amount as the round ones, and draw MUCH easier. Maybe the one bog D-Hole? Anyway, I do recommend the ones from Eastmall. Shipping is $12 and takes about a week to California, but the carts are MUCH cheaper than in the states. Something like $2.50 for 10 pcs. There poly is glued to the cart though. But that can easily be removed / replaced.