No. 690 Concrete Block Inspection Inserts:

Install special hook provided into center hole of the insert and maneuver it into cut-out block.  After the insert is lined up, pull and twist hook in all directions to tighten flanges on inside of insert to the block.  Insert should be about 1/4" x 3/8" recessed at finished position. Patent #D375574

Made for 3 1/2" cut-out block.

• No labor needed to prepare, strip, or dispose plywood covers
• No T-nail guns, air compressors, hoses or electric cords necessary
• No need to pull out nails
• No bulges of concrete to chip or grind off
• Inserts are recessed to allow room for stucco
• Holes in inserts make it easy to verify that the cell is poured
• Masons lay more block by not having to lift block over rebar