They work great with the Duke 390, I have them on my bike. The only thing to note is that they don't fit the stock gas tube, so you'll have to buy one or use the one on the bike and sand it down with 60 grit (strength) sandpaper. It also reduces the radius of rotation of the throttle, making the throttle slightly shorter, so keep that in mind. Personally, I don't find much of a difference, and I enjoy practicing throttle control this way.
Red L Motorcycle Gloves: Breathable, Touchscreen & Anti-Slip For Men Women | Hard Knuckles Protection For Motocross, BMX ATV MTB Cycling, Road Racing - COFIT
39 Review
Ride In Style And Safety With Xelement CF462 Ladies Black And Pink Tri-Tex Motorcycle Jacket
42 Review
Maximize Your Performance With SHIMA SX-2 EVO Motorcycle Shoes For Men - Reinforced Leather Riding Shoes With Ankle Support And Anti-Slip Sole
31 Review
🏍️ Xelement 7550 'Classic' Black Leather Motorcycle Chaps - Unisex, 36 Inches
35 Review