uniquegoods 10-50V 12V 24V 36V 48V PWM DC Motor Speed Controller CW CCW Reversible Adjustable Switch - - Amazon.com
15A 6V-90V Pulse Width Modulated PWM DC Motor Speed Controller – Envistia Mall
10 Amp 5-Stage PWM Charge Controller - By Zamp Solar – Overland Addict
MELIFE PWM DC Motor Speed Controller 10-50V 60A High Power HHO RC Driver Motor Controller PWM Controller Module 12V 24V 48V 3000W Extension Cord with Switch - - Amazon.com