Redshift Sports ShockStop Replacement Elastomer Kit - 50 60 70 80 90 Durometer Elastomers: Assorted Colors. Make your ShockStop Suspension Stem feel like new again with the Replacement Elastomer Kit. The kit includes one of each durometer elastomer letting you mix and match different stiffnesses to perfectly tune your ShockStop Stem.Includes 50 60 70 80 and 90 durometer elastomers (softest to hardest)