Train with instant stimulation level control. Two non-stimulating training modes: high performance pager and audible tone. Use combination boost control to instantly boost stimulation level up to 3 times stronger. Four training modes: nick, constant, high performance pager and audible tone. Ergodynamic one-handed handheld transmitter. Ultra compact receiver. 2-hour quick charge. Box includes: rechargeable batteries Li-Po, 2 inch antenna, black lanyard, 3/4 x 28 inch black collar strap, wall charger and splitter cable.