BIG RED car stands, they are made of high quality forged steel with welded frame construction. Each stand can support up to 6,000 lbs. The height of the stands can be adjusted from 11-1/4" to 16-3/4" and will fit most passenger cars. They have a special toothed rail that allows you to change the height quickly and lock it securely. The stands have a wide pyramidal base for added stability, and the large footprint ensures secure contact with the vehicle. These stands have been tested for reliability and safety in accordance with ASME standards.