General Tools MB560 3-1/2-Inch x 2-Inch Inspection Mirror with Magnetic Base The General Tools and Instruments MB560 3-1/2" x 2" Inspection Mirror with Magnetic Base is essential for seeing behind items or around corners Frequently used by machinists to observe the backside of a work piece while it is being milled, tooled or drilled The 3-1/2" x 2 oblong mirror provides crystal clear reflections and is adjustable via two universal joints to provide an optimal viewing angle The powerful magnetic base will clamp firmly to any ferrous metal Great for use with large and small industrial equipment