Aeroquip, if they still exist. Used them with 3" straps on a DM600 Mack flatbed with a Prentice Series G boom to secure dimension lumber, pallets of asphalt roof shingles, shakes, large glue-lam beams, siding, oak flooring and sheetrock, lotsa sheetrock. I was on the road 5 or 6 days a week in...