Wirthco 21073-7 Universal Adjustable Battery Hold-Down Battery Doctor hold-down secures the battery to the small or large "Replacement Battery Tray" (sold separately) Adjustable to size. 5/16" thread fits battery width 4 1/2"-7" Our corrosion resistant vinyl-coated low carbon steel hold-down comes with two 8 1/2" "J" steel bolts and wing nuts for securing the hold-down to the battery and thus the battery to the bottom tray (sold separately)