Wide Compatibility: 5000 Replacement Heads Suitable for Shaver 5000 Series S5370/84, S5370/81, S5660/84, S5590/81, S5290/88, S5210/81, Shaver AT790/40. High Precision Cutting System: SH50 replacement heads have a precision cutting system. Round head design perfectly protects your skin from scratches. Latest Upgrade: Replacement Heads Series 5000 has an ultra-thin head with slots for shaving long beards and holes for shaving the shortest stubble. Tips: After installing the blades of the 5000 Series replacement heads, drop a small drop of baby oil on each head and let the shaver run for 10 seconds. These steps will help ensure your shaver runs properly and more smoothly. Package: You will receive SH50 for 5000 series replacement heads.