6" x 1-1/2" Shock Absorbing Stem Mount Swivel Caster - 770 Lbs. Capacity | 7M-GDS150ASS6" x 1 1 2" Shock Absorbing Stem Mount Swivel Caster Part# 7M GDS150ASS This heavy duty spring loaded caster is the premium shock absorbing caster available for loads requiring 500 pounds of capacity or less. Not only does it protect sensitive equipment from shock loads and vibration but it also reduces noise during transportation and has the ability to roll over obstructions. The 7M GDS Series features a special NBR rubber based spring system instead