Tool is simple to use by clamping the hex handle in a vise, slide the hose onto the tip, twist back and forth a few times for a flare, insert the olive, slide back onto the tool to seat the olive and you are ready to use your hose.
Handle is anodized alum. and steel parts are cad plated finish. Tool is -3 on one side and simply spin the knurled nut off flip over and -4 is on the other side.