I've got the Tekonsha wireless unit and it does ok. If you have multiple trailers with brakes, you need to move it around from trailer to trailer. I leave mine on the track car trailer. The smaller trailers I tow don't have brakes so this setup works for me.
https://www.etrailer.com/Trailer-Bra...ha/TK94FR.html

I also got an adapter in line with this so the LED lights on the trailer don't set off the blinkers. Can't remember which one, but I think I listed in another post. I could look up if you get to that point.

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Daily Drivers:
- 2008 535i, 320,000km
- 2004 X5 4.4, 01/2004 production, 420,000km
- 1997 328i, 350,000km

Track:
- 1996 328i, track/race car, ~300,000km

Winter:
- 2013 Ski-Doo MXZ X 800 E-TEC, trail can
- 2007 Ski-Doo MXZ Blizzard 800 HO
- 2001 Ski-Doo MXZ 600 w/800 engine, exhaust
- 1978 Ski-Doo Olympique 340 (vintage race sled)
- 1977 Ski-Doo Olympique 340E