4mm outside diameter and 16-notch

See the chart in the images to help you choose the correct adapter for your needs

Specs: Available in 450mm and 480mm options

5" not recommended on rims narrower than 27mm

Fox Factory Transfer SL Performance Series Elite Dropper Post - 31.6mm - Internal - Stealth - 100mm Drop - 380mm Length - No Remote Supplied - 2024 PLP|Model Year 4mm outside diameter and 16-notchAt up to 167 grams (roughly 25%) lighter than the Transfer post, the Transfer SL is the lightest mainstream dropper post on the market. The two position design means the dropper can be ridden as either fully extended or fully retracted with size travel options from 27. 2mm x 50mm up to 31. 6mm x 150mm. With lever options for both flat bars and drop bars, the Transfer SL brings simplicity and lightweight performance to Trail, XC and Gravel disciplines.