Great product, I second mypennames review. Yes it is just two pieces of plastic bolted together, but the way in which it is bolted together is what you are paying for. The top piece of the green biscuit when on the ground and being stick handled will move up or down slightly in accordance to the direction that the puck is travelling in. This means that the centre of gravity will be on the opposite side to which it is travelling and thus does not tip over. This is what makes it so good on concrete and wood surfaces for example. Ignore that foolish review! This is a great training aid to improve stick handling off of the ice and behaves much in the same way a puck does on ice, nothing can beat the feel of that of course but this is a great substitute. Great for nailing those toe drag dekes and through the legs. Also try attaching weights to the end of an old stick to increase and improve muscle memory/strength and stick handling skills. I have noticed my stick handling getting better already and I have only used it a couple of times already.
Browsing hockey pucks offers I stumbled upon negative (one star) review of Green Biscuit. Although by itself rather unarticulated and vague and as such not credible, I felt compelled to correct it. I bought Green Biscuits directly (when it was not yet available via Amazon) a couple of years ago and used it for hockey passing/receiving practice mainly on concrete but also on asphalt floor. I was amazed with its stability. Contrary to other pucks, it practically doesn't stumble. You must literally force its turning around. The passing/receiving feeling is very natural and close to ice puck, certainly way better than with other, "monoblock" pucks. I did not shoot it into anything as manufacturer also explicitely states that it is not intended for shooting practice. Others also, whoever tried it, shared my opinion.