Vinyl Glass Door Roller

This is brass with what appears to have a name of Mbc on each side of it. Hard plastic wheels with a patent number of 1001b it appears on the side of the wheels. Looks like it says MBC Bearing on the side of the wheels too They are for a very heavy sliding door that has a breakage protection film on the glass that makes it extra heavy

It's about 6 inches long, about 1 1|2 ,inches wide and a little over half an inch wide at the top of it if you were looking down on it with the wheels on the ground