The KEYHOLE HANGER is used for aid progression - where bolt hangers are missing, damaged or a string of "rivets", round head or hex head bolts cross an otherwise blank face. When clipped with a full sized oval or D carabiner the KEYHOLE HANGER is secured to the stud, given the nut or round head is in good condition and of adequate size. Made from stainless steel these sleek KEYHOLE HANGERS fetch minimum 2,500 lbf on our test machine and are light enough to carry on your chalk bag biner for emergency use. Use SMALL size on 1/4-5/16" "button heads" and "drive-ins" and LARGE size on 3/8" "button heads", 3/8" POWERS 5-piece and FIXE WEDGE and TRIPLEX Bolts.