Cavallo Trek size 4 converted to Easyboot Trail (and Trail Original / Old Mac's G2)

Sizing across brands only works through the millimetre band, never the number. Cavallo Trek and Easyboot Trail (and Trail Original / Old Mac's G2) both publish in millimetres, so a Cavallo Trek 4 (hoof length 134 to 141 mm) is matched by finding the Easyboot Trail (and Trail Original / Old Mac's G2) size that covers the same length.

Cavallo sizes on length, then you pick sole width. If your width is 6 mm or more under your length, choose the Slim sole in that size; otherwise the Regular sole.

The Trail's length and width bands step in 5 mm increments and overlap heavily, so several sizes can look right. Fit to width first on this rounder boot.