I've had this carrier for many years, and it's still in use. I've had up to five boats attached to this thing, and probably could have gotten away with six, but we didn't have another one to throw up top. My current vehicle is limited to only three kayaks due to the design of the vehicle's roof rack. As long as the roof rack is wide enough, it will handle four kayaks.

As a side note, I only carried the five kayaks for a few miles under 35 mph! But with four up top, it'll handle freeway speeds just fine so long as your roof system can handle it. Thule, keep making this thing!

Bonus! They lock! What a outstanding material design.

Had for 4 years now and still love them. They hold all 4 of my small kayaks at high speeds for over hour trip many times.

When I got kayaks I was trying to avoid racks like the J style Hull a Port. I've had issues with boats shifting, and am not a fan of the design. The Stacker is a simple design that uses the crossbars to help keep the boat in place. Never had an issue with shifting, even on 8 hour drives with two boats. It's also the cheapest Thule option for more than one boat. Very happy with my decision. Just make sure you put the straps on BEFORE you put the boat on.

The Stacker is perfect for our 2 kayaks. Easy to install and use. Came with 2 straps.

We travel with 2 touring kayaks the first installation time to properly secure the kayaks was too long and now the whole process takes approx. 20 minutes the weaving of the strap through the centre post for the second kayak eventually gets easier the straps are very strong and hold the kayaks to the centre posts making for a tight and secure assembly. The only issue we have encountered is the tightening of the straps during wet weather I my alter the fitting to a ratchet assembly in lieu of the friction fit to negate this issue Many comments have been received with how the kayaks are mounted and secured these racks, the straps and the hardware are great quality and recommended.

Works Great for fitting multiple boats on a rack. If you are going to put one boat on each side I would recommend buying a set of the 15 ft. load straps.

If you are putting this on an Xsporter remember to use the Xadapt 3 adapter kit. There is a link to it in the technical specifcations area on this page. Not sure why Jay from a previous review couldn't stumble on that.

Great Product, use mine all the time and recommend to all my friends.

Had this carrier for several years. Has held up great. Would buy it again.

Simple for a beginner to set up and use without confusion.

These are my first set of straps, ever! So far I really like them but have only used them about 4 times. I feel a little more at ease leaving my SUP on my car when going out to eat after a paddle.