This engine is a screw in replacement for your stock engine in a Hanko Trident, Okluma DC1 and Malihini. This dragon engine will have your choice of primary and secondary leds in it. Some older versions of these lights may have a spring on the bottom (where the positive post of battery touches) of the stock driver, if this is the case you will need to replace the switch as well. New McClicky switches are available in the parts section of this site. Every engine includes a clear narrow Carclo optic. These are built to order and will be 1-2 weeks on average wait before shipping.