The double bollinger band indicator uses a normal bollinger band with a multitude of 2 and on outer band with a multitude of 3. The indicator shows momentum by the price being stuck between the higher or lower bands. If price is in the middle then it is a neutral zone. The band's moving average is a default of 20 sma but included there are two extra simple moving averages just as extra indicators. This is my first published code and the code is messy; however, it gets the job done nice and simple. (: Enjoy!