Looking for a decent creeper

The one I bought was from Harbor Freight
Basically the same design. Blow molded board with 6 casters. The problem was that the casters wouldn't swivel when I tried to slide under. I'm not a small guy...230 lbs....but it's supposed to be good for 300 lbs. No bueno.
The old creepers I remember as a kid had ball style casters. I find NONE of those in the market nowdays.