Specifications; M3; i/d 3.2mm; o/d 9mm; 1mm thick. M4; i/d 4.3mm; o/d 12mm; 1.6mm thick. M5; i/d 5.3mm; o/d 15mm; 2mm thick. M6; i/d 6.4mm; o/d 17mm; 3mm thick. M8; i/d 8.4mm; o/d 21mm; 4mm thick.
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