Will this creeper fit under my low-slung car or sports car?

At a low profile, it's designed to slide under most vehicles. If your ride sits extremely low or has custom suspension, test the clearance against your lowest point before committing to work underneath.

Do the casters work on rough concrete or gravel?

Casters roll smoothly on flat concrete and asphalt. Rough or uneven surfaces (gravel, dirt) will slow rolling — keep this creeper in the shop or on paved floors for best performance.

Can I use this creeper on a lift or jack stands for safety?

Never use a creeper as a substitute for proper lift equipment or jack stands. Always support the vehicle with appropriate safety gear rated for its weight. The creeper is a positioning tool only.