Versatile Sizes for Spools: This set includes three distinct sizes of spool caps (25mm, 30mm, 40mm) to accommodate different spool types. Each size comes in pairs, ensuring you have the right fit for standard, cone-shaped, or smaller spools, enhancing sewing efficiency. Thread Jam Prevention: Utilize these spool caps to shield the thread from catching on the spool's split edges, which can cause thread breakage, needle damage, or skipped stitches. This simple addition to your sewing setup helps maintain smooth operation and protects your machine. Ample Replacements: The package contains six white spool caps, ensuring you have sufficient backups to replace lost or damaged . These round discs cover the spool on the spindle, preventing thread snags during machine operation and extending the life of your sewing equipment. Broad Compatibility: Designed to fit a wide range of sewing and embroidery machines, these spool caps are compatible with most for and for models, as well as other . They are essential for anyone using models from the 3300 to 4400 series and beyond. Enhanced Sewing Experience: By stabilizing the spool and preventing thread entanglement, these spool caps a smoother sewing experience. They are essential for both novice and experienced sewers who want to avoid interruptions and maintain consistent quality. Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:White Material:Plastic Package Contents: 2sets * Spool Cap Sewing Machine Spool Pin Cap(2pcs for each 2.5/3/4cm) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.