System utilizes 3/8" grade 9 bolts (rated at 150,000 P.S.I tensile strength). Made in the U.S.A – Precision crafter from T6 aluminum, hardwood handle. Treehopper drill and 10 steps (bolts) weighs only 2.5 lbs. Drill and 10 steps will fit in the palm of your hand. Simply drill hole in tree – drill will automatically stop at proper depth – inset bolt into hole.