https://www.gobilda.com/8mm-rex-standoff-bundle-104-pcs/

Stock your warchest with essential standoffs with the 8mm REX® Standoff Bundle! Fancier parts might make the headlines, but the simple specificity of the exact-right standoff can be a lifesaver to your build in critical moments. Don't let something so small bring your project to a halt!The 8mm REX® profile is combination of an 8mm Round and a 7mm hEX profile. That's how its provision of fierce positive drive comes with the ability to ride in round bearings.

This bundle includes four pieces each of 26 different lengths of 8mm REX® Standoffs—up to 96mm!