4' BOX BLADE XB KING KUTTER'S XB-BOX BLADE is designed for rugged use by landscapers, farmers, homeowners, and in light construction. They are great for landscaping, land leveling, backfilling, grading, and many other applications. Each box blade is constructed with a 12" specially formed self-cleaning moldboard. They have 2 high carbon steel reversible cutting edges (one front and one rear). Each unit features flip-up heavy duty ripper shanks with replaceable heat treated teeth. The shank housing is a 2 x 4 box and the upper frame is constructed of heavy gauge steel with an all welded "A" frame for added strength.