Has a heavy-duty ratchet mechanism for high torque applications. Easy-squeeze technology helps reduce actuation force. Anti-jam magazine prevents jams and misfires and the surface guard prevents damage to underlayment material. Ergonomic design is weighted forward for comfortable use. Uses dewalt heavy duty staples series dwhtth700 available sizes 5/16 inch (8mm), 3/8 inch (10mm), 1/2 inch (12mm), also uses same range of stanley tra700 series heavy duty staples plus arrow t-50 heavy duty staples.