These have 2 holes. Each hole is can take a 3mm cord but I have also managed to get up to a 4mm cord though as well. It depends on if it can squash down. 3mm 4mm Cord Lock Adjuster. The more you buy the better the price per clasp.
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5PCS Pruning Shears Spare Spring Garden Spring for Pruning Shears Grafting Tool Scissors Components Stainless Steel Spring
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Twin Hole Cord Stopper. Choice of 17 Colours!
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5 Pcs Wire Diameter 2.0mm Compressed Springs Cylidrical Coil Compression Spring Return Release Pressure Spring Steel Coils 65Mn
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User Friendly Design: Conveniently carry and organize your work with the rope lock stopper, making it easy to secure and adjust your projects with ease. Item Type: Spring Cord Lock. 1 x Spring Cord Lock.
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Creamily 600PCS Wire Diameter 0.4MM Compression Spring Compressed Spring Y-Type Rotor Return Spring Support Customization
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27MM H X 14MM W / HOLE 8MM WIDE & 5MM HIGH. OUR SINGLE HOLE CORD STOPPER ADJUSTER IS MADE OF DURABLE. Plastic single hole cord lock is used to lock cord for convenient use, high quality steel spring loaded design.
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10Pcs wire diameter: 0.7mm torsion spring V-shaped rotating torsion spring 60/90/120/180-degree return and reset torsion spring
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10-100pcs White/Black Toggle Cord Locks Silicone for Face Mask Adjustable. The toggle stoppers simply squeeze together, and the cord lock can move freely up and down, when released, tension is engaged and the cord lock stays in place.
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5PCS Compression Spring Return Spring Steel Pressure Springs Tools Wire Diameter 0.4/0.5mm OD 3mm-12mm Length 10mm-50mm
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OUR QUALITY BARREL DOUBLE AND SINGLE HOLE PLASTIC CORD STOPPER. We have 6 Colours to choose from, of differentsizes and accommodate different cord thickness. Cord locks are used to lock cord for convenient use,spring loaded design.
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5PCS Pruning Shears Spare Spring Set Garden Spring for Pruning Shears Grafting Scissors Components Scissors Spring Part Tools
Aliexpress UK
27MM H X 14MM W / HOLE 8MM WIDE & 5MM HIGH. OUR SINGLE HOLE CORD STOPPER ADJUSTER IS MADE OF DURABLE. Plastic single hole cord lock is used to lock cord for convenient use, high quality steel spring loaded design.
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10PCS Cylidrical Coil Small Compression Spring Return Compressed Springs Release Pressure Spring Steel WD 0.4/0.5mm
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Silicon Elastic Cord Buckle Lock Adjustable Toggles Beads Stopper for Face Mask. Usage: Shoe lace, Para cord, Toggles. Silicone Cord Locks Toggle Buckle Adjustable Elastic Cord Stopper 10-100pcs. Silicone Cord Locks Toggle Stopper Adjustable Buckle DIY Making Mask 10-100pcs.
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65Mn Wire Diameter 1.8mm Compressed Springs Cylidrical Coil Compression Spring Return Release Pressure Spring Steel Coils 10Pcs
Aliexpress UK