Do I need a jack stand to use this?

Yes. Never work under a vehicle supported only by a jack. Always use quality jack stands rated for the load. The jack itself is for lifting; stands are your safety.

What's the difference between this welded jack and a standard bottle jack?

Welded construction means the frame is solid—no pivot pins to shear or bend under extreme pressure. Better for sustained heavy lifting like engine swaps or frame alignment work.

Will this fit under my car's frame?

Bottle jacks are compact by design, but confirm your vehicle's ground clearance and frame geometry before purchase. Test-fit is always the smart move on different platforms.