Nap thunderglo lighted nocks have ultra bright led illumination and feature an easy on/off feature.Thunderglo lighted nocks are crafted of a polycarbonate blend with an aluminum shaft making them extremely durable for long lasting use and life expectancy.Its universal collars will allow thunderglo nocks to fit most any arrow (g/x/h/s).Model: ThundergloColor: GreenQuantity: 6 Per PackMaterial: Polycarbonate/Aluminum