We carry both nylon rollers with sealed ball bearings and steel rollers on the truck, sized to fit the stem and bracket spacing common on doors from the 1990s-2000s building wave that covers most of this area, including Pharr's 2001-era stock. Nylon is quieter and doesn't need grease, which is the better call in a climate band like this one where heat keeps bearings running hot most of the year - steel rollers transfer more of that heat and noise into the frame.
We don't stock every roller size that's ever shipped on a residential door. If your house has an older track system or an odd aftermarket bracket, we may need to order a specific stem length, and we'll say so on site rather than force a part that doesn't fit. That's the one limitation worth knowing up front - most Pharr jobs match stock, but not every one does.