Threadless Matte Disks Size:2.5mm - Gray while the 12g post is

while the 12g post is front-threaded for 14g threaded ends

Clear borosilicate glass unless otherwise noted

This makes it a better choice for people who do not need to remove and reinsert their jewelry regularly

from Junipurr

Threadless Matte Disks Size:2.5mm - Gray while the 12g post isThreadless "hide it" matte finished disk end in implant grade titanium. Gray, dark brown, light brown, pink or yellow. This threadless end fits in any universal threadless post. Post sold separately, see below. **Threadless jewelry requires two parts to make a complete piece of jewelry: a threadless post w a fixed end and a separate threadless end. If you need a whole piece of jewelry, be sure to buy a threadless post to go with your end!