Almost every spare-part question that comes in starts with the same exchange: what is the model number, and what does the rating plate say. The two together are how a confirmed fit gets confirmed, and they are also the two pieces of information most operators don't think to read until something has gone wrong.
The rating plate is the small metal or printed label on the body of the tool. On drills and grinders it usually sits on the side or underside of the motor housing; on mitre saws it lives on the rear of the base; on sanders it lives near the trigger. The plate carries the brand, the model number, the input voltage and current, the no-load RPM, and sometimes a serial number. The model number is what matters for spares, and it usually reads as a letter prefix and three to five digits — 9558NB, GWS 7-115, DW717XPS, HR2470.
If the rating plate has worn away, all is not lost. The model number is usually moulded into the plastic housing somewhere on the tool body — the underside of the foot, the inside of the brush cap, or the battery rail on cordless tools. If you have the original part you're replacing, the part code stamped on it is an equally good identifier for brushes and bearings.
Brand alone is rarely enough. A Makita drill brush is specific to that tool's brush size and lead style; a DeWalt mitre saw brush is specific to its terminal and dimensions. The model gets you to the correct fitment in one step. Once you have the model, the brand-specific routes by part take it the rest of the way: carbon brushes, planer parts and blades, bearings and mechanical components, vacuum bags and filters.
If brand is your starting point rather than part type, the manufacturer directory covers every brand we stock parts for. If you'd rather start from the part, the tool parts hub is the better entry point.