The SpinOlution 12oz bobbin is crafted from durable Baltic birch with a built-in clip that holds your leader thread securely, making it quick and easy to start a new bobbin. The magnetic locking system holds the bobbin in place against the flyer rod, so changing bobbins mid-spin is fast and friction-free. Pollywog Exclusive The 12oz bobbin is designed exclusively for the SpinOlution Pollywog. The Pollywog 12oz flyer offers larger capacity than the wheel's standard 4oz flyer, ideal for spinners who want more yardage per bobbin without losing the Pollywog's lightweight, portable design. The 12oz flyer and bobbin are not compatible with any other SpinOlution wheel. Note: SpinOlution does not offer Wildflowers or Honeycomb engraving on the 12oz bobbin. Engraving is available for 4oz, 8oz, 16oz, and 32oz bobbins. Compatibility The 12oz bobbin fits the Pollywog 12oz flyer: SpinOlution Pollywog (with 12oz flyer) All 12oz bobbins use a fixed 1/4 In shaft diameter, so no measuring is required for this size. Specifications Capacity: 12oz Material: Baltic birch Shaft diameter: 1/4 In Magnetic bobbin locking system Built-in leader thread clip About SpinOlution SpinOlution spinning wheels and accessories are designed and crafted in the USA. Browse the full SpinOlution Bobbins collection for additional capacities from 4oz to 64oz.