GBA Nature Ring
The GBA Nature Ring is a Magical Ring that Link can obtain in Oracle of Seasons. There is no possible way to obtain the ring in Oracle of Ages directly, but it can be obtained through a Linked Game by using the Ring Secret.
When playing Oracle of Seasons on a Game Boy Advance console, Link will have access to the Advance Shop in Horon Village. There are three items available for sale in the Lynna Village Advance Shop. There is a Gasha Seed, the GBA Nature Ring, and another Seed Ring.
When worn the GBA Nature Ring has no effect at all. This is simply just a symbolic ring given to those who play the game on a Game Boy Advance console. A similar ring can be found in Oracle of Ages in the form of the GBA Time Ring. That ring, similarly, has no effect when worn.