OK so im just getting back in to playing the gutiar after 20 years of not touching it , and have really been trying to get better and explore and develop my skills, and i have to say these picks ( at least for me have been a game changer) all the other picke I was using prior to these ( some fairly good ...some really SUCKY)fail in comparison ....i play a lot of Bluse as well  as Rock and Metal especially Iron Maiden AC/DC type stuff and these bad boys are perfect...ok to the pick...there made of a nice hard plastic that so far has really held up ( ive been using the same one for a month) no chips or wear down....and they have the best thumb grip ive ever used built in on the pick on both sides so you get a nice non slipping grip action so weather your strumming fast or slow or picking hard or soft they NEVER slip ( and Ive found my picking skills and speed has increased and been more accurate since using these.) there the only I will buy! get them there friggin awesome!!!!!