When installing a handshower remember the round nut on the hose fits onto the wall end, either on the supply elbow or bracket. The tapered hose nut screws onto your handset, so that it slots into the cradle of your bracket or rail holder.
Always make sure a supply elbow is used at the wall outlet or a bracket that screws directly onto the wall outlet. The hose should always be fitted to one of these units. A hose should never be fitted directly onto the wall outlet as this will cause undue pressure on the hose.