Focal Resonance is a Dota 2 item of Immortal rarity. Current price — 4.16$. On DotaLoot it drops from 7 cases — open them and get Focal Resonance cheaper than on the market.
You can get Focal Resonance for free in daily DotaLoot giveaways or with Battle Pass levels. The fastest way is opening cases — noticeably cheaper than buying it on the market.
The current price of Focal Resonance is 4.16$. It is updated based on the Steam market.