Wind-lock Electrical Box Hot Knife Blades are designed specifically for rouging in Electrical Box receptacles in ICF Walls with the use of a 2-QC Hot Knife or SuperGroover. The Q-EBXK is a convenient pack that includes (1) 2-1/2in x 3in blade and (1) 4-1/2in x 3in blade, for cutting in single and double gang boxes.