i bought these picks because i mostly play bass and these are durable enough to withstand many many houars of my agressive picking.
these picks are the most durable ive tried and perfect exept of one dissadvantage, they get pretty slippery and hard to keep grip on with slippery hands.
in short these are great to have when you rehearse long houars and do not want to change picks all the time. but at a gig i would recommend dunlop gator grip instead.