Review on 🔒 CZC AUTO Hitch Tightener - Heavy Duty 304 Stainless Steel Stabilizer for 1.25 and 2 Inch Hitch, Rust-Free Lock Down Hitch Stabilizer for Hitch Tray Cargo Carrier, Bike Rack, and Trailer Ball Mount by Chris Horton

Towed a boat with 5500# for almost 5 years. Not only did this thing eliminate slack in the towing package, but it also made towing safer since sag under braking was virtually eliminated. It's hard to believe that the $12 piece made such a big difference. I ordered two other brands and they came with locknuts - not this block. But this knot is pretty tight and I don't think the locking nut adds anything other than increasing the time to remove (some car washes). Highly recommended for towing or trailer stowing.