This piece enables you to connect your eBike to the Folding Deer Trailer or Folding Cargo Trailer. 

Mules and Storms need 3/8.

Jager Mules/Storms need Jager hitch.

Jager Scout and Mav3 need 10mm x 6mm adapter.

Scout needs 229mm x 1.5TPI SDWT.

Flatlander, Grizzly, Timberwolves and Kodiak models need 12mm.