At my work we use wahl and oster clipper brands. I have a wahl but want to try the oster. My oster 76 came with the 000 blade. If someone comes in and wants a #2, what guard would I put on my 000 blade? Or if they want a #4 guard to make it a 1/2 inch long which guard would I put on my 000? I just heard the length is different between the wahl and Oster