All Quattro cartridges fit all Quattro razors. Conditioning Strip with Aloe & Vitamin E 4 Synchronized blades with patented blade coating Extra Lubrication Strip before the blades improves glide Prep Strip stretches the skin Performance Guarantee: Schick Quattro Power is unconditionally guaranteed. If you are dissatisfied call 1-800-Shavers, and Schick will replace it free of charge or refund your full purchase price.