Empire Level EM71JAMB True Blue 32-Inch and 78-Inch Magnetic Level Door Jamb Set True Blue vials are accurate to within .00050-Inch per-Inch in all 10 level and plumb working positions Dual molded rubber end caps for extreme shock resistance 300-Degreeview top-reading level vial rare earth magnets for super-strong holding onto ferrous surfaces Ergonomic hand holes