Easy to install. Clean the razor before installing. Ensure compatibility with your razor model. Fit: For Braun Series 5 8000 51S Replacement Foil Head & Blade. Compatible with all 51S models including: Type: 5643, 5644, 5645, 5646, 5647, 5649, 5751, 5757, 5758. Model No: 8970, 8975, 8985, 8986, 8987, 8990, 8991, 8995, 8595, 8795, 8581, 8583, 8585, 8588, 8590, 8781, 8783, 8790, WF1s, 510, 550, 560, 570cc, 590cc, 530s-4, 550s-3, 550s-4, 550cc-4, 560s-3, 560s-4, 565cc-4, 570cc-3, 570cc-4, 590cc-3, 590cc-4, 8385 C&R, 8374, 8377 - Series 5, ContourPro. Note: To check the replacement part number, open the sideburn trimmer on the shaver to find the part number (e.g., 10B, 30B, 32, 51S). Grid cover: 4.4 x 2.5 x 2 cm. Knife head: 3.1 x 1.7 cm. Color: Silver. Material: Nylon + stainless steel. Package contents: 1 x mesh cover, 1 x knife head. The package includes only the items listed. Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowance: +/- 1-3 cm.