These economical over-the-road heavy duty truck axle shims a re our lowest cost option. With average compression strength and hardness these shims are available in a large variety o f sizes and offer the technician a cost effective means to c orrect caster on over-the-road trucks and trailers. NOTE: Or dering one Part Number supplies Six Shims in a box. When pla cing order spring pad length and width are needed. California Residents WARNING