Wood-Knocker Concrete Inserts are installed onto wooden forms used to support a newly poured concrete floor slabs, roof slabs or walls. When the forms are stripped, the color-coded flange is easily seen embedded in the concrete surface allowing attachment of steel threaded rod or threaded bolts in sizes ranging fron 1/4" to 3/4" in diameter. The unique six-sided impact plate offers resistance to rotation within the concrete as a steel threaded rod or threaded bolt is being installed.