5 Pack, 3/8", MC/BX Cut In Connector, Connects Metal Clad Or Armored Cable In Old Work Electrical Box Installations, No Tools Are Required When Assembling To The Cable Or Box & The Anti-Short Bushing Is Pre-Assembled, Will Not Fall Out During Transit Or Installation, After Installing The Old Work Box In The Wall & Fishing The Cable Through The Box, Simply Snap The Cable To The Fitting & Snap The Fitting Into The Box, Easily Removed Without Tools & It Is Reusable.