Originally it was a 3.5k tow dolly I stretched to fit a rear engine XRRA buggy. The frame is 1"x1" x1/8 square tubing with 7/8" crusher shafting inside where it counts, 4"x4"x1/2" square tubing for main runner. Weigh's close to 850lbs. Has a tad bit of tongue weight when loaded but it has to follow.. I've used it pretty hard for 12 years and it's still hanging in there.We’re gonna need more info on this trailer!