These mountain bike tires were a good replacement for the over-priced tires that I originally had on my son's mountain bike. He thought it was fun to constantly skid on the old tires until there were holes in the tires, so I needed to get some new tires. These new tires have an aggressive tread pattern to them and do not have a directional indicator on the sidewall. They grip well in dirt & gravel and have good stability when inflated to 32-40psi. They were extremely easy to install and I was able to do so without having to use tire levers. The description mentions that the tires are puncture resistant, so hopefully this will help prevent flats. These tires are heavier than some of the other over-priced tires, but work well for bikes where weight isn't a major concern. The rubber material seems durable, so I'm curious to see how well they hold up over time.