I'm not talking about the "o" rings, what I'm saying is there were what looked like a rubber flat washer made on to each end of the new filter. Where the one taken out did not have them. When I looked down into the housing it was obvious there was a seat for this flat rubber washer thing to fit into. I was just concerned that there might be a difference in the SRT6 and the regular Xfire filters since the old one did not have these on it. I thought it may be a screw up from the factory on the original filter.