Unfortunately the manufacturer has discontinued this product. However, the manufacturer suggests the below as an alternate. This paddle works for the 5 gallon and 10 gallon mobile mixer.
Man-U-Fab R-10-10 Asphalt Paddle For Asphalt/Concrete 10gal Mobile Mixer
Related Products: Asphalt Paddle For Asphalt/Concrete 5 Or 10gal Mobile Mixer