The ProTek R/C LiFe Car Transmitter Battery Pack is intended for use with the Futaba 4PK, 4PV and 4PX Transmitters. Lithium battery technology is evolving. With cell dimensions that fit anywhere a standard Li-Po battery will and rapidly increasing capacity, LiFe chemistry will soon set the standard that all others are judged by. With the ability to deliver 1000+ usable cycles, and a life span up to 4 times longer than Li-Poly batteries (when cycled under the same discharge conditions), these batteries offer the user an excellent balance of performance and value. LiFe batteries are more durable than Li-Poly and are able to handle a higher level of abuse when compared to Li-Poly without the risk of pre-mature failure. Unlike Li-Poly, LiFe cells can be stored in a fully charged state with little to no loss in stored power, and can be discharged deeper with less risk of damage to the cells. Most importantly, LiFe batteries are SAFE! There is no risk of combustion! LiFe cells will not catch fire or explode when over charged, or after a deep discharge.