REPLACEMENT HEAD FOR SERIES 3 SHAVERS: Compatible with Series 3 shaver models 300s, 310s, 3010BT, and all Series 3 foil razors. SHAVING PERFORMANCE: The 21B replacement head includes 3 independently floating shaving elements. These flexible units are ergonomically designed to adapt to facial contours for a comfortable and close shave. QUALITY CONSTRUCTION: The S3 replacement head features precision tooth comb technology and mesh design. The comb captures more hair per stroke, while the mesh helps prevent hair pulling, enabling a comfortable and efficient shaving experience. MATERIAL: The S3 wet and dry replacement head is made of high-quality materials and is waterproof and rust-resistant, allowing use in both wet and dry conditions. It is recommended to replace the Series 3 foil and cutter every 18 months. EASY TO INSTALL AND CLEAN: Remove the old shaver head and click the new 21B head into place. Includes a cleaning brush for easy maintenance. Clean the replacement blade quickly by rinsing under running water or use the included brush for a deeper clean. Color: As Shown Material: Plastic + Metal Package Contents: 2 x Shaver Heads 1 x Cleaning Brush Note: Light reflection and different displays may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3 cm.