What is this component and what is it used for?
10 ohm +/-5% wirewound resistor (probably inductive, perhaps fusible but it's hard to tell). Called a &quot;cement&quot; resistor. Made by KOA (Nagano, Japan-based company). If it's 13mm long, then 1W rating. J is the JIS or EIAJ standard code for +/-5% tolerance.
Here is a datasheet.