Two good ones available...
http://www.actionmodelcentre.com/pro...QC%2DTQBOOSTER
http://www.rcdynamics.co.uk/Products.html
The RC Dynamics one is well proven and bullet proof. A post in the Wanted ads on here might get you one someone no longer needs.
The alternative for just a few pounds more is the
Core RC 1S speedo. For your extra money you get something that does an excellent job, has no need for a booster and is ideal for 13.5 1S. If you are running a 13.5, then you can dispense with the fan as well. It is BRCA legal. If you will need to invest in the motor and cell as well, check out their package deal for all three on the same website. HTH
