Skil PWR Core 20 20V 4-1/2'' Angle Grinder with Quick Change Guard Paddle Switch with An Angle Grinder That Can Tackle Any Task. The SKIL 20V 4-1/2 inch Angle Grinder is a powerful workhorse that can grind metal and more with user-friendly features including restart protection. Designed cordless for your convenience, ensuring you can charge it quickly and make it last longer.