The official Japanese Pokémon website has announced that the Pokémon GO Plus Exclusive Ring Option (Pokémon GO Plus 専用 リングオプション) will go on sale on July 15th, 2017 for 400 yen only at the Pokémon Centers, Pokémon Stores and the Pokémon Center Online. The ring attaches to the back of a Pokémon GO Plus and when you put your finger through the ring, it allows you to easily operate a Pokémon GO Plus with the palm of your hand. From July 15th, 2017 on-wards, those that purchase the Pokémon GO Plus from the Pokémon Center, they will get the Pokémon GO Plus Exclusive Ring.


Those that purchase a Pokémon GO Plus and/or the Exclusive Ring Option will also get a sticker sheet that has decals featuring a Great Ball, Ultra Ball and Master Ball which can be placed on the front of a Pokémon GO Plus.


Source: http://www.pokemon.co.jp/info/2017/07/170714_p03.html