You get a set of 2 pulleys by HUICAO with this purchase. I actually got these for my BF, I had no clue what you could do with these. I had to do some research. I found out a few things that are actually cool that you can use pulleys for. You can use pulleys to make a dog pulley system, crafting projects, kayaks, canoes, construction, household, perfect for garage, clothes line, home made gym cable system and more anything thing you can think of. These are 304 stainless steel, anti-rust, strong load bearing and very durable. I hope whatever my BF has in store for these he is happy with them. Here are the dimensions : Wheel Diameter: 15mm; Groove Width: 6mm; Eye Diameter: 11mm; Total Height: 60mm; Weight: 41g; Max Load: 35kg. The original primary use for pulleys was to make it easier to lift heavy items. The pulley is a simple machine made with a wheel and a rope, cord, or chain.