The Hillman Group 375665 Strike Anchor, 1/2 X 3-1/2-Inch, 25-Pack Product Description Used for anchoring into concrete only. Anchor is inserted into hole, nail is struck and expands the anchor locking it in place. Removable with a claw hammer if necessary. From the Manufacturer Used for anchoring into concrete only. Anchor is inserted into hole, nail is struck and expands the anchor locking it in place. Removable with a claw hammer if necessary. Features Strike anchor size is equal to hole size Nut and washer can be pre-set for desired embedment Removable with a claw hammer if necessary Used for anchoring into concrete only USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.