Fast just doesn't do these justice. I used these to anchor electrical boxes to a cinder block wall and finished the whole job in less time than it takes to tell the story! Just drill a hole, slip the anchor through the material to be fastened to a masonry structure, hammer home the pin, and you're done. A zinc alloy body provides plenty of pullout resistance for light duty applications such as installing electrical boxes or shelving brackets. Once the pin is set, the anchor is locked in place, making removal almost impossible - ideal for tamper proof installations. Typical pullout values in 3000 psi concrete are 400 lbs for 3/16" dia anchors, 800 lbs. for the 1/4" dia anchors. Industry safety standards recommend 1/4 of the test values for actual applications. In severe service applications, additional safety factors may be warranted. Age and condition of wall material will cause performance variations. Made in USA.