Lightweight extruded aluminum forms this 24 In. I-Beam frame. This level is engineered to meet the demands of the home handyperson. Three bright yellow vials are set for accuracy. The solid set, replaceable Roto Vial® protective plastic lenses an vials. A groove in the bottom of the frame is ideal for rounded surfaces such as pipes and conduit. Large hand holes provide comfort and ease when moving the level. A hang hole on one end allows for easy storage when not in use. Store in a Professional Level Case (#SLPLC24), sold separately, to protect your level and extend its life.