The Mirka ARP300-B 3" Rotary Battery Polisher is a cordless spot repair polisher built for professionals who need control in tight spaces. This is a rotary polisher designed for polishing small areas and correcting localized defects. Model Number: ARP300-B. If you do paint correction, detailing, or refinishing work where a standard-size machine is more tool than you need, this one makes a lot of sense.

What sets this cordless polisher apart is how focused it is on small-area work. The 3 inch backing pad gives you a better fit on compact panels and curved sections, while the rotary action provides the direct polishing contact needed for targeted correction. Mirka also gives you variable speed control on the trigger, which is a real-world feature, not filler. It lets you start slow, spread compound cleanly, and bring speed in as the pad settles, which helps cut down on mess and gives you more confidence on delicate finishes.

The ARP300-B is also built around a brushless motor, which is exactly what you want in a compact professional polishing tool. Brushless design means lower maintenance, efficient power delivery, and less extra noise compared to older brushed setups. Mirka specifically positions this tool as light, nimble, ergonomic, and quiet, and those points matter when you're doing repetitive spot work for long stretches. A compact polisher only earns its keep if it stays comfortable in the hand and easy to guide, and this one is clearly aimed at that kind of use.

Because it is cordless, you are not fighting a power cord around fresh paint, trim, mirrors, or tight repair zones. That freedom of movement is a real advantage in automotive detailing and body shop work, especially when you're moving around a vehicle or working in confined spaces. No cord also means less drag on the surface and less hassle when you're making quick corrections instead of setting up for a full panel polish.

From a jobsite practicality standpoint, this Mirka rotary battery polisher is about precision and convenience more than brute size. It is not trying to replace a larger machine for full-vehicle correction. It is the tool you reach for when the job is isolated, access is limited, and finish control matters. At 1.8 lbs assembled weight, it stays light enough for one-handed work and controlled polishing passes without feeling top-heavy.

On the system side, the ARP300-B works as part of Mirka's cordless setup. The manufacturer listing for this version identifies it as the tool-only configuration, with batteries and charger sold separately, while Mirka also offers a kit version with 5Ah 12V Li-ion batteries and charger. That is worth knowing before you order, especially if you are adding this as a second machine to an existing Mirka cordless polishing setup.

Who should buy it? Automotive detailers, body shop techs, paint correction pros, and refinishing specialists who routinely work on spot repairs or tight sections will get the most from it. Serious users who already understand when a compact rotary polisher beats a larger machine will appreciate how purpose-built this tool is. If your work is mostly full-size panel polishing, you may want a larger polisher first. If your work regularly includes mirrors, bumpers, pillars, blend areas, or defect correction in confined zones, this is the kind of specialized tool that saves time and gives you better control.

Small polisher, very specific job, exactly the point

The Mirka ARP300-B 3" Rotary Battery Polisher is the kind of specialty tool that earns its spot fast if you do spot repairs, paint correction, or detail work in tight areas.

• Who it's for: Pros and serious users doing automotive detailing, refinishing, and localized polishing where a full-size machine is too bulky.
• Why it stands out: Compact 3 inch format, brushless motor, cordless freedom, and trigger-based speed control make it easy to handle and easy to trust on delicate work.
• Worth knowing: This is the bare tool version, so plan on batteries and charger separately if you are not already on Mirka's cordless setup.

• What kind of tool is the ARP300-B? It is a cordless rotary polisher designed for polishing small areas and spot repair work.
• What size backing pad does it use? The ARP300-B uses a 3 inch backing pad.
• Does it have a brushless motor? Yes. Mirka specifies a brushless motor for low maintenance and efficient performance.
• Is this a kit with batteries and charger? No. This ARP300-B version is the tool-only configuration, so batteries and charger are sold separately.