Brass
These replacement flask spouts will fit the Treso flask, powder valves and most Italian made powder flasks except the baby size .31 caliber flasks. Spouts are made of brass and can be cut with a tubing cutter to obtain in-between charges. 15 grain. Caution — ALL TRESO FLASK SPOUTS AND POWDER MEASURES ARE TO BE USED ONLY FOR BLACK POWDER OR BLACK POWDER SUBSTITUTES.