Milwaukee Red Lithium batteries are the next generation in Lithium-Ion technology. They are compatible with all products in the M12 cordless tool system. Red Lithium battery packs provide unmatched runtime. They ensure high performance and durability for the professional tradesman. Lithium-ion battery delivers longer life and run-time with fade-free power. Battery fuel gauge displays charge status on tool. WARNING: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www. P65Warnings. ca.gov.