Quad/Inline Rollers by the company Athlopaidia. They can be used in two forms, as Quad Rollers or as Inline Rollers.

Quad Rollers are the classic four-wheeled skates, with two wheels in the front and two in the back, and usually a rubber brake in the front. They have a wider base, which offers even weight distribution, while their wheels are wide and flat without edges. This makes them more stable and possibly preferable for amateurs. You can easily maneuver by slightly shifting your body weight to the right or left. Suitable for even surfaces, they offer manageable speed in a straight line, but are not ideal for those who want to move at high speeds. They help in gaining confidence, learning balance, and developing control. Their design puts less pressure on the ankles.

Inline Rollers feature a series of aligned wheels located towards the center of the frame, under the boot. They increase speed more easily compared to Quad Rollers, because they have a smaller friction surface with the ground, making them ideal for fast skating. High speed requires more balance and control, which is why experienced inline skaters develop techniques for speed regulation and stopping.

These particular rollers are adjustable. The ability to adjust the size makes it easy to quickly fit the roller to the user's foot. This way, you have the ability to find exactly the size that fits your foot, and at the same time, they are ideal for use by different people.