(hex:AF) (Red) and 
(hex:AF) (Blue) are glitch items in Pokémon Red and Blue.They are both Rival's effect glitch items. When one of these glitch items is used outside of battle, it will bring up the Pokémon menu as if using an evolutionary stone, but with unknown compatible Pokémon. The menu can be cancelled with B to enter a glitched state in which the player can walk through walls that are one tile thick.
When the player attempts to use the glitch item from within battle, it will result in Professor Oak's message that it isn't the time to use the item.