Sliding glass door rollers

Hi, we are looking for replacement rollers for our sliding glass door. The current rollers have ULTRA on them, with the logo, but no other markings that I can find. The height of the housing is 1.1 inches. THe width of the top part is 6 mm. The diameter of the wheel is around 1 inch. I'm pretty sure the wheel is metal. Photos are attached. Let me know if you need any other info. Thanks!