Has anyone heard anything about these? Or ever bought them

 

I've only ever heard of Underdog performance pulleys

http://underdog-performance.com/

 

Iv never understood the purpose of an underdrive pulley. What does it do?

 

I wanted the underdog performance pulleys but that company is going out of business and you cannot get the kit anymore. Just whatever they have left of random pulleys. That's why I was wandering if anyone has ever heard Anything about the JET pulleys. But I guess it's the same basic concept, so maybe I'll be the guinea pig and buy them and post a review on em.

 

im curious to know if they are worth buying. anyone ever used em?