Abell-Howe® Foundationless Base Mounted Floor Crane. The Abell-Howe J904R Series was developed to be a foundationless jib for industrial applications requiring only 6″ concrete depth. Requires epoxy anchor bolts. Jib crane provides 360 degree rotation on a tapered roller bearing providing full capacity vertical and radial thrust loading. Concrete floor mush be at least 6″ thick and contain wire mesh reinforcement, in minimum soil pressure of 2,500 psf and minimum concrete compressive strength of 3,000 psi. Jib crane must be centered on a square foot area that is free of cracks, seams, control joints and walls. Made in the USA.