Also, you can look here:
tippmannparts.com - Super R/T kit
OR even here for more info:
Another OG thread about this
By the way, I have installed one of these kits on my gun. It keeps the air pressure more constant, it helped me really dial it in better. For such a low price, I would recommend it to nearly anyone using R/T. Just be sure to get the extra bit of macroline!