4x137 is an off-road utility pattern. You will find it on Can-Am and other ATV / UTV applications. We stock 325 wheels drilled 4x137.
Measuring is simple: count the studs, then measure the diameter of the circle they sit on. Five studs are measured from the far edge of one hole to the center of the one two holes away; six or eight studs across opposite centers. Ordering the wrong pattern is the most common fitment mistake — if your measurement falls between two patterns, confirm with the vehicle's spec sheet first.