I need a wider lens. Trade my Canon 24-105mm IS for your Canon 16-35 f/4 IS. My 24-105 IS is in great shape rarely used. Your 16-35 must likewise have working IS and clean glass. Might consider f/2.8 III version. I only want Canon lenses. If for example, you wish that you zoom would work for portraits, and could use the 24-105mm, I need one that works better for my landscape pics, and could use your 16-35mm. Lets work something out. Frankly, I never use my 24-105. I believe that I would need to include some PayPal cash payment to you in addition to my lens.