Hey Quentin, how's it going? The line you're asking about sounds like a D size level line (i.e. no taper...don't expect it to cast real well) Notice I said SIZE; they used to go by diameter, and depending on the material/construction the weight could vary quite a bit between manufacturers. Most likely, that D is about a 6 weight. If it were a double taper, it would be an HDH. Good luck. My first fly rod was a True Temper tubular steel rod (real lightweight wonder).