The new Nocturnal nock by Double Take Archery Raises the bar on lighted nocks. The new design is sleek and simple. It requires no magnets and there are no contact points that could potentially break. There is a switch on the nock that is activated by the force of the string when you shoot your bow. You might be wondering if it turns on when you put it on the string then. That was my first thought and it turns out that the switch will not turn on when you nock under normal conditions. It will stay on until you manually turn the switch off which works good for activities such as bow fishing where you are shooting constantly and do not have time to be deactivating between shooting. To turn nock off just use a field point to slide the switch to the off position. Along with the usability of the nock it also offers a long 20 hour plus battery life for longer life of the nock. Another key advantage of this nock over others is that it only weighs 8 more grains than an average nock. That is half as much as other brands. Being lightweight like that means you will be able to easily switch back from your practice nocks to your lighted nocks without having to resight your bow.
The Nocturnal Nock is available in red, green, yellow, and pink. They are made in all nock sizes and are easily installed in your arrows. Here is the link for the nocks http://shop.archerycountry.com/browse.cfm/2,1280.html