I have seen several C4 traction controllers from smartrise and have had lots of problems with them. The V2 hydraulic controller might be ok but the C4 version really sucks and is a complete failure. The boards are compact and small not because they have done a great job designing tiny boards! Its because either they don't know the required clearance between components or they decided not to follow the safety codes! The high voltage 120V inputs cannot be so jammed and small. It is simple physics and code! That's why they fail and catch fire all the time. This is my personal experience and understanding after analyzing several broken boards.