These stop bit head replacements for our onboard dust extractors feature tool-free attachment. Easily change or replace in seconds. When a bit head wears out, just remove it, snap on a new one, and keep working. Use them with our DEWALT® dwh303dh or d25303dh onboard dust extractors as part of an OSHA table-1 compliant solution when installing virtually any concrete anchor system, including mini-undercut+ and smart di+.