Plumb site allows for dual views of vertical vials. Heavy duty aluminum with shock absorbing rubber end caps and an ergonomic rubber handle. Accuracy to within 0.001 inch per inch. Kapro's 170 non-magnetic aluminum I-beam level has wall thickness of 2.0 mm. This level comes with a milled surface, and includes the patented Plumb Site Dual-View vertical vial, top-reading horizontal vial and an additional vertical vial. All vials have a protecting cover to keep the vials clean and clear. Additional features are shock-absorbing end caps and an ergonomic rubber-coated handle.