A bit hard to strip anything under 5mm but works well on everything else . It lacks the grip nodules at the base of the drive wheels to pull small wiring through under 5mm but when you remove the guide/ guard you can apply downward pressure to the wire to gain grip & then it will strip down to 1.5mm . If you have enough copper wire stored up it will pay for itself within a week no doubt . I will definitely recommend this item for anyone stripping wire . So much better than a Stanley knife lol