The level can be hit countless times with any trowel and the dead-blow patented "protective shield" protects the frame by transferring the energy directly to the work surface. The frame will not warp or twist A level is a mason's second most important tool. STABILA'S "Trowel Proof Mason's levels" (patent pending) feel solid in the hand, will withstand thousands of   drops without any negative effects and have an accuracy certified at 1/32" over 60".