Cane Creek Eesilk Elastomers The Cane Creek ee Silk suspension seat post offers 20mm of vertical compliance/travel via an elastomer that is position in the center of the seat post. 20mm may not seem like a lot of travel, but it's just enough to increase control during rough sections of trail and reduce fatigue during long rides. Three different elastomers come with the seat post in different densities to accommodate riders anywhere from 100 lbs. to 260 lbs. Additional elastomers can be purchased to change how firm the seat post feels. The firmest elastomer (extra-firm) is designed for riders between 260 lbs. and 330 lbs. Five different elastomers are available for individual purchase ranging from extra-soft to extra-firm. Available Elastomers Extra Soft: 40 Durometer Soft: 50 Durometer Medium: 60 Durometer Firm: 70 Durometer Extra Firm: 80 Durometer | Cane Creek | Eesilk Elastomers Medium (60 Durometer)