Feature:1. Accessories: Assist and replace old sewing machine accessories to ease your sewing work.2. Material: High quality materials can be used for a long time, making your sewing work easier.3. Applicability: Suitable for Singer, for butterfly heavy machine sewing machine.4. Tools: Practical tools can effectively avoid jamming the spool during machine operation.5. Practical: The spool caps is a part connected to the spool pin, which can hold the thread in place and help the thread to unfold correctly instead of jumping during sewing.Specification:Item Type: Spool CapsMaterial: PlasticSpecification: 1 Set (1 Cover, 1 Stopper As a Set)Applies To: for Singer for Butterfly Heavy Machine Sewing Machine Thread PlugProduct Function: Replace Old Sewing Machine Accessories.Package List:1 Set Spool Caps