300pcs Threaded Insert M2 M2.5 M3 M4 M5 M6 Insert Nut Brass for Plastic 3D Parts. 20PCS M4 4mm. 20PCS M4 6mm. 20PCS M6 6mm. 20PCS M6 10mm. 3: Equipped with a plastic box, you can classify Hex Socket Set Screw in an organized manner, more convenient to carry and take out.
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