For example this well specified Facom SXL.171PB. Extending 1/2" ratchet with flex head, quick release and 72 teeth. Appears to be no removable access plate?
http://docs-europe.electrocomponents.com/webdocs/12b2/0900766b812b2922.pdf
http://docs-europe.electrocomponents.com/webdocs/12b2/0900766b812b2922.pdf