Ultimate durability with self-sharpening blades made of similar steel as in the aerospace industry, designed to stay sharp and resist even the toughest conditions.Advanced precision for a closer shave with 72 high-performance self-sharpening Dual SteelPrecision blades made of Swedish steel for up to 165,000 cutting actions per minuteTo ensure optimal performance of your face shaver, use only genuine replacement Philips Shaving HeadsCompatible with Philips electric shavers Series S8000 (S86XX), S9000 (S97XX, S99XX) and Series Prestige (SP98XX); not Compatible with older S9000 SilverThis set includes 3 Packs of shaving heads (9 Blades Total) with Dual SteelPrecision blades | Philips | | Norelco Series 9000/S9000 Replacement Shaving Heads | SH91/52 | 3 Pack | Best Buy