I really expected a set of four. Of course it would have made it what I paid, $8.67, very cheap for the price, but it doesn't have a lock. I should have looked more closely, it says "1" unit! hit me on the head! I'm assuming that 'one' is fine, but wow the price isn't. why would you sell one How many unicycles are there? And even though I bought it 3 days ago, today's price is $14.22 (because I love it SO much!). Then why did I find a set of 4 stop wheels on Prime for $14.99 (which I just ordered by the way)? It does not make sense. I think this one will be a backup if I break any of the others I just ordered. If anyone complains that I missed the "obvious" then they are right. I did, but it wasn't that obvious when I was looking for 4 wheel kits.