Shock absorbing casters reduce noise, protect cargo and extend caster, wheel and bearing life. Hamilton now offers two styles of shock absorbing casters. Our original patented design with its unique “floating” axle under the springs represents the more economical choice. The second, our new premium aerospace design featuring Hamilton’s newest Spinfinity maintenance- free swivel construction and a unibody spring housing providing up to 200% greater spring travel and a wider operating capacity range.