vacuum breakers on hose faucets

Any recommendations on whether and how to update my old hose faucet (35 years old) to incorporate a vacuum breaker or other anti-backflow valve?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
pat writes:

Cheap screw-on item with setscrew, if permitted by local code.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.