Ninja Total Crushing Stacked Blade assembly item# 316KKU770. This came from a model DB751A but will fit many models, please check before ordering.
Compatible with: BL640, BL641, BL642, BL642W, BL642W1, BL680A, BL681A, BL681C, BL682, BL682W, BL685, BL687CO, BL688, BL770, BL770A, BL770BRN, BL770W, BL771, BL771C, BL772, BL772QBK, BL772QCN, BL772QPL, BL772QT, BL772QWH, BL773CCO, BL773CO, BL780, BL780C, BL780CCO, BL780CO, BL780WM, BL910, BL910BRN, BN700, BN700C, BN701, BN701C, BN750, BN750C, BN751, BN751C, BN800, BN800C, BN801, BN801C, BN801BBYC, BN801NP, BN805A, BN805CCO, DB751A, BL780WM, BR201AMZ, BR201CCO, BR601AMZ, CO750B, KS500
See photo gallery for the actual item you will receive and it's condition.