The Mirka AROS-B 325 3" max 12V Orbit 2.5 mm is a cordless random orbital sander built for mobile detail sanding and finish work. This is a random orbital sander designed for spot repairs, body-in-white sanding, and post-paint applications. Model number AROS325-B-NV. If you need a compact sanding tool that can move freely around a panel, part, or repair area without a hose or cord getting in the way, this is exactly the kind of machine that makes the job easier.

What makes this sander matter is the combination of a 3 inch (77 mm) backing pad, 2.5 mm orbit, and 12V brushless motor. That setup points this tool toward controlled surface prep and finishing rather than broad-area stock removal. The smaller pad helps you work tight areas and localized defects without sanding farther than you need to, and the 2.5 mm orbit is well suited to finer, more controlled sanding where surface quality matters.

Mirka also built this unit around mobility and user comfort. The lightweight, ergonomic body is meant for one-handed use, and the low-vibration design helps reduce fatigue during repetitive sanding work. That matters in automotive and refinishing environments where you may be moving from one repair zone to the next all day and need the tool to stay comfortable and predictable in hand.

The cordless layout is the real practical advantage here. On small repair work, dragging an air line or power cord around the vehicle, bench, or paint area wastes time and increases the chance of bumping finished surfaces. A cordless random orbital sander like this lets you grab the tool, hit the repair area, and move on. For techs doing spot correction or post-paint sanding, that kind of workflow improvement is not a small thing.

For real-world shop conditions, Mirka notes sealed protection against dust and water, and the tool is suitable for both dry and wet sanding. That gives it more flexibility than a basic cordless sander, especially in refinishing work where process changes from one sanding stage to the next. The sealed design also makes more sense in dusty environments where fine sanding debris is part of the job every day.

This sander also fits into the larger Mirka system. It is compatible with Mirka power tool batteries and works with the myMirka app, which adds connectivity to Mirka's sanding ecosystem. If you are already using Mirka abrasives, accessories, or cordless tools, that shared platform is a real benefit. Just note that battery and charger are not included with this version.

Who should buy it? This is a smart pick for automotive refinishing pros, paint correction work, detail sanding, and anyone who needs a compact orbital sander for controlled surface prep in smaller areas. It also makes sense for serious users who already have Mirka batteries and want a purpose-built cordless sander instead of trying to force a larger general-use sander into precision work.

Mirka AROS-B 325 3" max 12V Orbit 2.5 mm is a specialist tool that earns its keep

If your work is centered on spot repair, finish sanding, and moving fast without a hose or cord, this is the kind of compact sander that feels right immediately.

• Who it's for: Automotive refinish techs and detail-focused users who need a compact cordless sanding tool for smaller work areas.
• Why it stands out: The 3 inch pad, 2.5 mm orbit, low-vibration design, and cordless 12V brushless setup make it purpose-built for controlled finish work instead of general sanding.
• Worth knowing: This version is bare tool only, so battery and charger are not included.

• What kind of sander is this? It is a cordless random orbital sander designed for spot repairs, body-in-white sanding, and post-paint applications.
• What is the pad size? It uses a 3 inch (77 mm) backing pad.
• Can it be used for wet sanding? Yes. Mirka states that it is suitable for both dry and wet sanding tasks.
• Does it connect to the myMirka app? Yes. It is compatible with the myMirka app.