My M25 works great to haul my 42' Spartan toy hauler. 18,000 lbs GVWR.
The only issue I have is that the manual and my M25 do not agree. There are no second groove.
"Lift flip lock and pull lock bar outward approximately 1/2". While holding lock bar in this position, drop flip lock back onto the lock bar. Pull lock bar to its full extension. Flip lock will drop and engage second groove."
The bar is smooth with only one groove. Perhaps you should make those changes necessary in the manual.Rating: [5 of 5 Stars!]