... of high resolution and compact size 3.1220mm Portable Video Borescope Features: Color camera of high resolution and compact size2. ... surfaceApplicable for inspection & observation beyond human eyes' reach, mainly on automobile/aviation engines, pipes, and mechanical components, etcPORTABLE VIDEO BORESCOPE SPECIFICATIONSOUTER ... SUPPLYPower: 3×AA batteryWorking hours: >3 HRS Portable Video Borescope