A pair of brushes. Made with high-hardness, wear-resistant graphite carbon brushes.  

For NAGRA units, over time most of the carbon brushes get worn down, and the motor might not work properly, so they need to be replaced.  

Note: Different models have different brush lengths, so you'll need to sand them to fit yourself. The carbon brush, not including the cylinder, is 0.197 in (5mm)—adjust it based on your machine.  
The carbon brush does not include the spring. Use the original machine’s spring.