I lost the mounts for our Cygolite Metro 1100 & older Cygolite Metro 500 lights for family bikes.
This fits the 22mm bar on Cannondale Quick CX3, Cannondale Quick 20, Cannondale Quick 24, & likely other models.
The standard part fits the newer Cygolite Metro, Ranger, & Streak lights. The 32mm variant covers the older mounts.