Holmes Hobbies CrawlMaster ESC (Electronic Speed Controller). The CrawlMaster Mini ESC is designed to fulfill the needs of comp RC Rock Crawlers looking for a small, yet powerful and versatile ESC! It harnesses the power of 32 bit technology to offer the smooth, quiet, and torque-dense driving you desire in an extra small package! The ESC comes pre-soldered and ready to plug and go! It is conformal coated for water resistance, but Holmes Hobbies recommends extra coating with CowRC's Cow-Formal coat (CPP-C46011344 - Sold Separately) if you plan to submerge the ESC.