The Firenock circuit is the brain of the system.  

There is a total of seven Firenock circuits for the FLNS.  And of the seven, three functions are represented in up to three sizes: standard, slim, and ultra-slim.

These circuits are for Firenock "C," "D," "D2," "D3," "F," "J," "M," "Q," "S," "U," "V," and "Y" styles. 

   •   H: This is the most popular circuit of the entire series.  It is the standard-sized hunting circuit.  Our hunting function stays lit for up to 21 days after launch and is perfect for big game like white tail deer.
   •   T: This is the standard-sized target circuit.  Our target function automatically turns off 17 seconds after launch and is perfect for practice, competition, and bow-tuning.  Additionally, due to its reliability, Firenock target system equipped arrows are the only lighted nocks legal for IBO and ASA competitions.
   •   I: This is the standard-sized intermittent or blinking circuit.  Our intermittent function stays solidly lit for six seconds after launch and then blinks for up to 21 days.  Due to the “halo” effect that occurs when a light blinks, this function is great for ground-blind and heavy cover hunting.  This effect can also be used in emergency situations since, at full power, its light can pierce up to two miles in total darkness.

These circuits are for Firenock "A" and "E" styles.

   •   N: This is the slim hunting circuit.  See “H” for details on the hunting function.
   •   K: This is the slim target circuit.  See “T” for details on the target function.

These circuits are for the Firenock "G" style.

   •   Z: This is the ultra-slim hunting circuit.  See “H” for details on the hunting function.

   •   0: This is the ultra-slim target circuit.  See “T” for details on the target function.

Main Components

There are four main elements to a Firenock circuit.  Note that all seven circuits are only different via their programming.

   •   LED: The LED, of course, is what makes our system a lighted nock.  Equipped with a 11k lux and 15° beam, it’s designed for extreme and focused brightness.  For every Firenock circuit size/function available, there is an option of six LED colors (red, orange, yellow, green, blue, white/clear).  We usually recommend red on red unless you're colorblind (then yellow, green, or blue) or shooting indoor (then white/clear to combat fluorescence).
   •   G-switch: Definitely the most expensive and advanced part of our system, this switch is made up of a ball and spring that can measure and only measures 65Gs of uni-directional energy.  This is what signals when to turn on/off your LED without an actuator e.g. a button.
   •   Integrated Circuit: This little black dot contains what many call the “chip.”  It's made up of a digital timer, a motion sensor, and a fuzzy logic computer.  These three subcomponents work together to recieve, evaluate, and respond to the signals from the G-switch.

   •   EZ-Coil: See notes below.

EZ-Coil System

Due to many requests for a simpler connection between the battery and the circuit, as of 2014, the dual-loop cross-lock system (above left) has been replaced by our original standard: the EZ-Coil (above center).  It is 24k gold-plated for reliability and, as its name suggests, eases the process of dis/connecting the battery from the circuit.  Note that on ultra-slim circuits ("Z" and "0"), the stack coil is utilized instead of the EZ-Coil due to size constraints since they do not have room for the EZ-Coil.