FitDesk Clamp-On Extender for 3.0 Exercise Bike & Standing Desk, Adjustable Laptop Stand, Bike Desk Attachment with Mousepad, Cup Holder & Tray, Fits Up to 17" Laptop, Treadmill Tray

I got these extensions for my fitdesk 3.0 & knew to get the extensions with the cup holder on the left extension. The three tabs on each side did NOT slide into the slots on the desk. I took a furniture clamp with soft plastic jaws and slowly pressed the extension tabs into place. I see where others have had good luck with WD-40 or lithium spray lubricant on the tab surfaces.The coffee mug holder (slotted for the cup handle) holds a cup securely, but I have to wait until I'm saddled up to put a cup in place if it is anywhere near full. The side to side jostling when swinging a leg across the bike will easily spill a lot of coffee/tea very quickly. The cup holder is on the left, so right handed riders may have to haul a cup over their keyboard/tablet for each sip. Drinks and electronics are a shaky combination in most situations, anyway.The desk is stable with the extensions firmly seated on the tabs. Total width with the extensions in place is 32 inches, too wide to be maneuverable through some tight doors. The tightness of the mounting tabs discourages frequent removal and replacement of the extensions. For my situation I could use only the right side if I had a tight doorway. Canned beverages rarely give me a problem in the high friction desk surface, and would work on the right side only.Overall, I'm happy with the product. I had hoped to get it at a better price, but Fitdesk has little competition in this price range and I know this more useful setup will encourage me to spend more time exercising while computing or watching the boob tube. The included mouse pad is a really useful add-on because it bridges the seam between the main desk and the extensions, allowing me to use a mouse in place of the jumpy touchpad on my Logitech K400+ wireless keyboard.

Nice to have the extra space but the cup holder isn’t deep enough so stuff will spill out.

It works great as an extension to the fit desk. I like having room for a mouse pad and not feeling cramped while using the fit bike. The only thing I did not like is that during installation I had to really force the extension in place. I felt like i was going to break it but it snapped into place and haven't had a problem since.

Perfect for the FitDesk 3.0. Am able to use my computer with my mouse (and drink in the nifty drink holder). Not too tricky to remove (once you get the hang of it) so that I can fold the Bike down for storage.Only bad thing is that it needs a mouse pad to cover the part where the extension meets the original tray to smooth it out a bit.

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These were not hard at all to install if you watch the video on the product page. These attachments add considerable surface area to the desktop. I don't love that the cup holder is on the left, since I'm right-handed. The slit for a coffee mug handle is a thoughtful touch, but is there really anyone who drinks hot coffee while working out? Left-handed, no less? (So your right hand is free to type?) That's some serious multi-tasking! Sadly, the attachments are not sturdy enough to reliably bear the weight of heavy books or someone pressing down hard to write. My greatest wish, besides the cup holder being on the right, is that the flaps could fold down so they don't take up extra space while not in use.

This is not easy to install unless you have the upper body strength of a gorilla.

These are great but make it too wide to roll through a standard interior doorway. Based on plastic tabs used to keep these locked in place, I am weary to take them on and off repeatedly.