Here is an accessory bottle jack for the post-war Chevrolet and GMC 1/2 ton pick up trucks. This bottle jack has been cleaned, oiled and tested. Testing was successfully lifting a '51 GMC 1/2 ton. Fully closed it measures 7" and fully extended it measures 16". Gear movement is good. It still has its original paint. The A stamp is the mark of Ausco Corporation of St. Joseph, MI. The attached drawing shows 55-66 placement under the seat. I am not sure exactly which years this jack applies to as there is very little information out there. Please check your application and ask any questions before purchase.