Within 18 months, your will cut an average of 6,000,000 hairs. In accomplishing this substantial task, the cutting parts will gradually wear out and your shave may become less and comfortable. That's why recommends changing your 's foil and cutter block 18 months to maintain your 's maximum performance. For an efficient shave day. Fitment: for Series 3 (320-4, 340 w/d-4, 350-4, 380-4, 390-4) and Triple Action Free Float shavers. Compatible with: for Series 3 300s, 310s, 320s, 340S, 350cc, 390CC, 3000BT, 3010s, 3040s, 3050cc, 3070cc, 3080s, & 3090cc Electric Shavers head should be replaced eighteen months, Replacing your head gives a 25% better shave. For performance; clean regularly. This item is an economical afforable replacement part. you can renew your head with such good replacement part Material:Plastic + Metal colour:Black + Silver Package Contents: 2 * head 1 * clean brush Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.