Skulltec knuckle pads size:thin pink and spring mounted striking ball for 1 and spring mounted striking ball for a multi functional training bag that benefits and improves athletes of all sizes and skill levels Skulltec knuckle guards feature two different sizes: 1 4 for heavy hitters with sore knuckles and 1 8 for those who just needed a little more knuckle protection inside their boxing glvoes Skulltec knuckle pads are a favorite amongst the boxing community Skulltec knuckle guards feature two different sizes: 1 4 for heavy hitters with sore knuckles and 1 8 for those who just needed a little more knuckle protection inside their boxing glvoes