Be careful ordering M-18's on This site, there are knock offs pretending to be oem, It took me three orders to get real OEM Batteries. If Walmart were a good business, they would kick those knockoffs off their site. I would even be willing to test them, but They don't seem to care. I even had one seller threaten me saying I tried to rip them off and that their lawyers would be calling me. I welcome that call as I video taped the entire opening and testing of their crappy batteries. If the price seems too cheap it's most likely not real. Hold the power button for three seconds, a real M-18 will go through tests and the lights will flash, The fake ones do not.