Features: 1Accessories: Assist and replace old sewing machine accessories to ease your sewing work. 2Material: High quality materials can be used for a long time, making your sewing work easier. 3Applicability: Suitable for Singer, for butterfly heavy machine sewing machine. 4Tools: Practical tools can effectively avoid jamming the spool during machine operation. 5Practical: 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. Item Type: SpoolCaps Material: Plastic Specification: 1 Set (1 Cover, 1 Stopper As a Set) Applies To: for SingerforButterfly Heavy Machine Sewing Machine Thread Plug Product Function: Replace Old Sewing Machine Accessories Package List: 1 Set SpoolCaps