ZIPP Service Course SL 120MM 17 Degree 31.8MM - Black

Zipp chooses Torx-head bolts for its stems and aero bars why? It comes down to the way the tool head interacts with the bolt. Common hex tools tend to strip the bolt head if the bolt is over-torqued. This is especially true with lightweight bolts.
Zipp wanted to be able to use a lightweight bolt with reliable performance. Bolts on stems and aero bars are critical to safety – having a reliable bolt is crucial. Zipp chose a bolt size that was best suited for Zipp stems; T25. The standard Torx tool head for an M5 bolt is a T25. The T25 is becoming a go-to bolt in the bicycle industry. What’s more, the T25 tool is common in bike shops or hardware stores and is readily available alone or in multi-tool sets. For your convenience, Zipp includes a T25 wrench with all stems and aero bars. The Torx head is more robust that hex-head bolts and will not easily strip