The SCN56 Medium Coil Nailer is a superior siding tool that drives full round head nails from 1-7/8in. 2-1/2in. in length and from .092 .099 nail shank diameter. The SCN56 is a lightweight, rugged and dependable multi-purpose coil Nailer. The SCN56 coil Nailer has a unique mode of operation. The SCN56 allows the operator to select either a dual action or restrictive mode of fastening by simply switching the trigger No need to change parts!