METRIC allen wrench. you can buy it at any tool store
Thanks for the reply it was a #10 metric. Sorry to say I didnt own any metric allen wrenchs before. However it wouldnt work for me. Once I got the bike high enough to see under it I could tell the previous owner had stripped it out. That was the main reason I was having an issue. I had to drive a quality craftman 3/8 extenion into the plug to remove and replace it. Was starting to look like it was going to have to be drilled and tapped out.