3 Vials - (1) Level, (2) Plumb. Accuracy of 0.0005 in/in (0.5mm/m). Center Vial Provides Bridge on One Side of the Center Vial to Allow End User to Scribe a Continuous Line. Non-Marring, Shock-Absorbing Rubber End Caps. Bi-Material Hand Grips, 2 Hang Holes.