Ultimate Penetration - Heaviest arrow in the Carbon Express line for ultimate penetration and knock down power. Innovative Built-in Weight Forward? Technology - Superior down range accuracy with a broadhead. BuffTuff® - World's toughest carbon arrow finish in Mossy Oak® camouflage pattern. Predator Vanes - High performance compact design for added arrow velocity and greater accuracy. Bulldog? Nock Collar - unrelenting strength and durability for nock end impacts. Straightness: .005" max. Weight Tolerance: 1.0 grain. Models: 250 10.4" long, .402" spine,.304" dia. Models: 350 11.3" long, .345" spine, .308 dia.