I just got a set of the reds in concert from Butler Music p-hill off ebay. They are monofilament and I haven't put them on anything yet. They may be fluorocarbon ... I don't know. Says they are made in Argentina. What bugged me about this purchase was even though the strings were like 6 bucks delivered, the mailman left a note in my mailbox requiring me to go to the post office to pick them up because the seller shorted the postage by 44 cents. Well the seller gave me a tiny rebate but it musta cost me at least a gallon of gas and an hours time going to the post office to pick up the strings. Expecting the Mele Braddah in the mail in a week and maybe I can put them on it... or I can put some Martin's on it... not sure how these reds compare to Martins (which I use mostly).