The Philips OneBlade QP420/50 replacement set provides two 360 flexible blades designed to trim, edge, and shave hair of any length. These blades are crafted from durable stainless steel and feature a 360-degree design that adjusts to the natural curves of your face for a smoother experience. To protect your skin, they include a dual protection system consisting of rounded tips and a glide coating, making them suitable for both wet and dry use. Each blade is built to last up to four months, assuming two full shaves per week, and includes a built-in replacement indicator icon to let you know when it is time for a change. This pack is compatible with all OneBlade handles, including the QP25xx, QP26xx, QP27XX, and QP28XX series, as well as OneBlade Pro models such as the QP6504, QP653x, QP654x, and QP665x. Please note that these blades do not fit the QP1XXX, QI1XXX, QP15XX, QP652x, QP651x, QP662x, or QP6505 handles.