Upgrade an existing 2800 or 2850 XL Professional timer to the current model 2900 XL Professional timer. 2800/2850 does not need to be fullu functional to qualify for this trade-in upgrade program. 2800/2850 timer is shipped to RaceAmerica, a factory new 2900 timer is return shipped back with full 90 day warranty. All existing sensors and emitters used with the 2800/2850 are fully compatible with the 2900. 2850 track cables are compatible with 2900 but not only a limited number of enhanced features are available with 2850 track cables. Scoreboard displays require a code upgrade to be compatible with the 2900 timer.