Tandem Roller Assembly ID

Wheels probably 1.5". Bad picture, wasn't centered over wheel. After lubricating rollers, placed back on slider. Wheels wouldn't rise enough off bottom guide. Not sure if rollers are damaged/out of round or if housing in vinyl slider is damaged, allowing the assembly to retreat into housing in vinyl frame. Will start by simply replacing existing rollers. Hopefully previous owner used correct rollers for this vinyl dual pane