This 23 gauge pin nailer is designed to meet the needs of professional woodworkers who want to do fastening nearly invisible. PIN138 is designed to counter-sink 1-3/8" pin nails into hard materials like oak and provides the option of using 23-gauge headless and headed pin nails from 1/2" to 1-3/8" length. The long life, maintenance-free motor requires no oil to be added and keeps the work surface clean. The rear exhaust is to keep contaminates away from work surface and the dry-fire lock-out alerts the user to re-load nails and eliminates empty nail holes.