Product parameters Product size d: represents thread diameter L: represents length (n 'does not include head length) k: represents head thickness dk: represents head diameter p: represents the pitch of the thread Note: About the packing: < /p> Use transparent plastic bag packaging, convenient to use and store. Regarding chromatic aberration: The products are all taken in kind, but it is inevitable that there will be have slight chromatic aberration due to the shooting light or display configuration