Part Number: 904749 This part is compatible with the following machines: Porter Cable DA250B 15 Gauge Angle Nailer Each package contains 2 Nailer Collars.The actual product is subject to the picture Purchase Notes:Pleases make sure the part number of new replacement matches your original equipment before ordering. If you encounter any problem, feel free to let us know. We will be more than happy to reply your message within 24 hours.