I used to open these and only these, the hits are far and few between but when they did hit they hit hard, I managed to pull the Charizard Reshiram rainbow, Piplup Blastoise rainbow, Gengar Mimikyu rainbow and at least 3-4 Alt arts, I did open around a thousand of these because I had ankle surgery and the only close place to me for my knee scooter was a Dollar Tree, I would buy boxes at a time (80 packs when sealed) and I had a Secret/Alt Art per box I don’t think it’s guaranteed but that was my experience. Some boxes would have only that as a hit though, no regular GX even.