 CRT screens had much deeper cabinets compared to flat panels and rear-projection displays for a given screen size; it was largely impractical to build or use CRTs larger than .The CRT disadvantages became especially significant in light of rapid technological advancements in LCD and plasma flat-panels, which allowed them to easily surpass these size limitations while also being thin and wall-mountable (two key features that were increasingly being preferred by customers).CRTs can emit a small amount of X-ray radiation as a result of the electron beam's bombardment of the shadow mask/aperture grille and phosphors.