The Mirka AROS-B 350 3" 12V 5mm Sander w/o Batt/Charger, model AROS350-B-NV, is a cordless random orbital sander built for mobility, control, and finish work in smaller repair areas. This is a cordless random orbital sander designed for spot repairs, body-in-white sanding, and post-paint applications. If you need a compact sanding tool that moves easily around a vehicle or workpiece without a hose or cord getting in the way, this is the kind of machine that makes sense.

The combination of a 3 inch (77 mm) backing pad and 5 mm orbit tells you where this tool fits. It is sized for localized work rather than large panel sanding, and the orbit is suited to efficient material removal while still keeping the tool controllable for finish-sensitive applications. That makes it a practical choice for technicians doing blend areas, small defect correction, prep between coating steps, or repair work where accuracy matters more than covering a huge surface fast.

Mirka builds this unit around a brushless 12 VDC motor, which is the right call for a cordless sander meant for regular professional use. Brushless design helps with efficiency, run time, and reduced maintenance compared to brushed systems. Just as important, the tool is described as lightweight and ergonomic, which matters on a sander more than people think. A compact sanding tool that is awkward to hold gets old fast. A compact sanding tool that stays balanced and easy to guide gives you better control at the edge of a repair.

One of the bigger selling points here is Mirka's focus on low-vibration sanding. That is not just a comfort feature. Lower vibration helps reduce hand fatigue during repetitive sanding passes and can make it easier to keep a more even scratch pattern when working on visible surfaces. For post-paint correction and repair prep, that kind of control is worth paying attention to because it affects both finish quality and how long you can work efficiently.

This sander is also built for real shop conditions. Mirka specifies sealed protection against dust and water, and it is rated for both dry and wet sanding tasks. That broadens where the tool can be used and helps protect the internal components in dirty sanding environments. For automotive and refinishing work, where dust is constant and wet processes are common, that is a practical feature instead of a brochure bullet.

On the system side, the Mirka AROS-B 350 3" 12V 5mm Sander w/o Batt/Charger works with Mirka power tool batteries and connects with the myMirka app. That gives users already in the Mirka ecosystem an easier way to keep tools on the same platform rather than mixing battery systems. It is worth noting that this AROS350-B-NV version is sold without battery and charger, so it is best suited for buyers who already own compatible Mirka 12V power tool batteries or who intentionally want to build a custom setup.

Who should buy it? This is a smart fit for automotive refinish techs, collision repair shops, detail-oriented paint correction users, and professionals doing small-area sanding where mobility matters. It also makes sense for serious users who want a dedicated compact sander instead of forcing a larger tool into tight work. If most of your sanding is on broad flat panels, you will probably want a larger machine for production speed. If your work is precise, localized, and finish-sensitive, this AROS-B is right in its lane.

Mirka AROS-B 350 3" 12V 5mm Sander w/o Batt/Charger is a specialist tool, and that is a good thing

This is the kind of compact cordless sander that makes a lot of sense when your work is precise, repetitive, and finish-sensitive.

• Who it's for: Automotive refinish techs, collision repair shops, and serious users handling spot repairs and post-paint sanding.
• Why it stands out: Cordless mobility, low-vibration design, wet or dry sanding capability, and a compact 3 inch format that is easier to control in small work zones.
• Worth knowing: This is the bare-tool version, so battery and charger are not included. Great if you are already on Mirka batteries, less ideal if you are starting from scratch.

• 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.
• Can it be used for wet sanding? Yes. Mirka specifies that it is suitable for both dry and wet sanding tasks.
• Does it use a brushless motor? Yes. The Mirka AROS-B 350 uses a brushless 12 VDC motor.
• Does it connect to the myMirka app? Yes. The product is listed as compatible with the myMirka app.