Roto-Stick is an Item card that was first introduced in the Pokémon Trading Card Game in the Prismatic Evolutions expansion, first released in Japan as an SV-P Promotional card. This card allows a player to look at the top 4 cards of their deck, reveal any number of Supporter cards they find there, and put them into their hand. The other cards are then shuffled back into the deck.
Trivia
The Roto-Stick's Japanese name is a portmanteau of ロトム Rotom and 自撮り棒 jidoribō (selfie stick).