For mounting on Gillette razor ProGlide power, these blades represent the epitome of expertise in mechanical Gillette shaving: Glide perfect, better shave without pressing too hard and therefore without irritating, springs under the blades to ensure permanent contact skin and a ball "joint" flex sleeve junction / head to follow the contours of the face, easy to clean, durable, wear indicator ... In one word: perfection. Is the price, about 5 blade ... but at a closer look this fault bit is nicely perspective to the life of the blades and therefore of a price it becomes an investment.