From the Manufacturer
With the 30-Inch heavy duty Hangman mirror and picture hanger with WallDog anchorless screws you can quickly and easily hang mirrors, pictures and wall decor up to 300-Pound. The Hangman Products removable bubble level is included and the Hangman System supplies all the hardware needed for wall installation. The brackets are heavy-duty aluminum. Mounting holes are punched on 4-Inch centers.