Features:Magnetic insert firmly holds the fastener in the socket for easy installation/removal. Prevents fasteners from dropping into restricted areas where they can be difficult to locate and/or retrieve Magnetic insert can be left in or removedIncludes nineteen pieces: SAE and Metric sets combinedThe 19 Piece Metric and SAE Magnetic Socket Inserts Set includes 19 pieces:3/8”, 7/16”, 1/2”9/16”, 5/8”, 11/16”3/4”, 13/16”, 7/8″10mm, 11mm, 12mm13mm,14mm, 15mm16mm, 17mm, 18mm19mm On Oct-24-16 at 14:48:48 PDT, seller added the following information: