Butane cartridges last up to 12 hours each

To best take advantage of that

#7 membrane - hard stiffness (use less than or equal to 15oz in front of V-Box)

minimizing additional travel costs

Competition Electronics ProChrono LTD hide_stock Butane cartridges last up toInternal and external refinements with updates to the circuitry and enclosure design Built in full featured operating system with multiple shot string memory and statistics Sensing system compatible with a wide variety of light conditions and projectiles Faster internal shot clock for improved accuracy to + . 5% or better Made in the USA quality at an affordable price Two year warrantee against defects in material and workmanship, and a 1 2 price