The Style "L" bobbin case brake spring fits inside APQS Smart Bobbin Cases. It reduces bobbin overspin by applying pressure to the bobbin as it releases thread. Do not use a bobbin case brake spring in conjunction with Magna Glide bobbins
The Style "M" bobbin case brake spring fits inside APQS Big Bobbin Cases. It reduces overspin by applying pressure to the bobbin as it releases thread. Do not use a bobbin case brake spring in conjunction with Magna Glide bobbins.
