Cannondale HollowGram KNOT Stem -6 Deg 90mm BlackThe Cannondale HollowGram KNOT Stem -6 Deg. The stem is made of a lightweight aluminum alloy that is also quite durable. The stem works with the HollowGram KNOT or SAVE SystemBar to provide the adjustability of a two-piece bar set-up, while having the low drag of a one-piece. This stem is available in 80mm, 90mm, 100mm, 110mm and 120mm sizes.884603798768