Mounts to the carb heat shield.  Excellent hand machined and finished part.  Exact copy of OEM in Stainless Steel. Expensive US sourced stainless.
 
These can also be purchased from datsun-roadster-parts.com (Paul Wells) or Sincitydatsuns.com (Brian Zana) 
 
Email about a  combo deal with a new 1600 heatshield for 200.00!