The norelco hq8 is replacement head from Philips that give you a clean cut by removing both longer hairs and short stubble. Super Lift and Cut action lifts hairs to cut below skin level for a closer shave. The low-friction SkinGlide shaving surface slides smoothly along your skin for a close, easy shave. The HQ8 replacement heads are compatible with the following Philips Norelco series: 7100 series, 7200 series, 7300 series, 7700 series, 7800, 8800 series, PT/AT700 series, and PT/AT800 series. If you do not see your model listed here, use the compatibility tool to determine the correct replacement head for your shaver. Replacing the blades heads every 6 - 12 months is still cheaper than purchasing a new razor.