Knowledge Base, a volunteer effort by Catharine McNally & Tina Childress, provides an extensive list of clear mask and face shield vendors. Due to high demand, please contact the vendors directly for more information.
While NDC cannot recommend a specific vendor, you can ask your question to the NDC listserv to see what other colleges and universities are using. Some also started to make their own. You should also review the information from the Center for Disease Control (CDC) or as outlined by your employer or school prior to buying or making any clear masks or face shields to ensure they provide enough protection.