Pokemon GO's evolution can be as simple as using the required amount of candy, but often rarer evolutions will require an evolution item.
These are consumables that can allow you to not only fill out your Pokedex, but also unlock some impressively powerful creatures.
One such item, the Sinnoh Stone, can make 22 creatures evolve, so it's worth getting hold of.
Here's how to do just that.
Pokemon GO: How To Get A Sinnoh Stone
There are a few ways to get Sinnoh Stones, but none are guaranteed.
That means you'll want to complete as many of these tasks as possible - especially since you can only use it once.
Arguably the steadiest method of nabbing a stone, you'll need to complete a Field Research task each day for seven days.
At the end, you'll have a chance to earn the Sinnoh Stone, but it's not guaranteed.
Go Battle League Reward
Speaking of PvP, try competing in the Go Battle League for a chance to earn a Sinnoh Stone as a mystery item.
Battling Other Players
You might earn a Sinnoh Stone from battling another player.
Battling Team Go Rocket Leaders
You might earn a Sinnoh Stone from battling a Team Go Rocket Leader.
For more Pokemon Go content, be sure to check out our guide to catching Magnezone.
And, with Halloween rapidly approaching, check out our Halloween guide!