A mid-range line of foil electric shavers positioned between the entry-level Arc 3 series devices and the more advanced Arc 5 models. The main design advantage of the 4th series is the upgraded shaving head, consisting of four independent curved elements. Typically, the design includes two ultra-thin foils for a close shave of short hairs, one specialized foil for capturing long stubble, and an additional combination trimmer for trimming flat-lying hairs. This four-step unit covers a larger area of the face in a single pass, noticeably reducing the overall shaving time and minimizing mechanical stress on the epidermis. The inner blades are traditionally made of durable Japanese steel with precision 30-degree nano-sharpening, ensuring an easy cut close to the root without pulling.

Technically, most Arc4 models feature a flexible suspension system for the shaving elements. The head can make micro-movements in all directions, smoothly adapting to the anatomical contours of the cheekbones and chin. More expensive versions in the series are equipped with high-speed drives that maintain a consistently high blade oscillation frequency until the battery is fully discharged. The lack of overloaded digital displays is compensated for by concise LED indicators on the handle, providing battery status information, and the high mechanical reliability of the entire design. The only exception is the more expensive Arc4 ES-LA63 model, whose handle still features a small monochrome display.

The practical use of this series is focused on convenience and portability. The fully sealed housings allow grooming to be combined with shower routines, the use of any familiar gels or foam, and quick cleaning of the cutting elements under running water. Built-in lithium-ion batteries provide up to 50–65 minutes of cordless operation, while the five-minute quick-charge function allows the device to be quickly prepared for one session. The ergonomic handle with a non-slip coating ensures a secure grip, while the pop-up trimmer located on the back makes it easy to adjust the shape of sideburns and mustaches.