The one I use on my Aventon Aventure 2 is the Qikour 31.8 Bike Stem Adjustable 0-60 Degree Bicycle Stem Handlebar Riser Extender for Road Bike, Mountain Bike, MTB, BMX (Only Fit 1.25"/31.8mm Handlebar). They have 3 different sizes. I watched a lot of different Youtube videos and it seemed to be a good one so I took a chance. I really like it and it works well for me. I purchased it on Amazon.