Direct Drive Air Compressors
Direct drive compressors are highly portable, with a compact design, and provide plenty of air capacity from vertically-stacked twin tanks. Inside, the compressor is constructed of cast iron with a pump that's kept splash lubricated. If used with consistently sufficient oil, the oil lubricated direct drive compressor should provide long term service without ever needing maintenance.
As well as being long-lasting and reliable, oil lubricated direct drive compressors run more quietly because of the sound muffling qualities of oil. If you have a lot of nailing projects to do and will be using the machine for extended periods, this is worth bearing in mind.