A loading unit includes a shell assembly and a locking collar. The shellassembly hasan annular ring that defines a locking slot and a proximal opening. Theproximal openingconfigured to receive a distal end portion of the surgical instrument. Thelocking collar isrotatably disposed about the annular ring. The locking collar has a bodyincluding a flexibletab that has an inwardly extending lock. The locking collar is moveable aboutthe annularring between a locked and unlocked configuration. In the locked configuration,the lockpasses through the locking slot and into the proximal opening of the annularring. In theunlocked configuration, the body of the locking collar is rotated about theannular ring fromthe locked configuration to move the lock from within the proximal opening.
