An automated drone that will heal you when not at full health. Initial price is $40. The drone generally will appear from the first level, regardless of difficulty, and is also useful in unlocking "The Back-Up" use item which requires you to have 4 drone helpers at once.
Each healing drone will heal for 5hp/tick for a limited amount of time when not at full health. They will then need to recharge before being able to heal again.Arms Race has no effect on it.