Tekin's B1 and B1-R bring exceptional brushed technology to mini scale vehicles. The B1 is small, less than 1" square, yet powerful enough to run any micro brushed motor available (up to 380 size). On-Board Temperature Indicator and Lipo cutoffs bring extra safety and highly reliable operation. The B1 has thousands of possible settings right on-board with Tekin's Quick-Tune Programming and is also capable of extensive tuning and updates when used with Tekin's HotWire PC Interface (sold separately). The B1 can be used with NiCd, NiMH and Lipo batteries and is ROCK CRAWLER SAFE for use in rock crawlers with 2S lipo and 540 size 55 turn or higher motors