Too thick for my Low Volume Technica boots. I went to Corsa, which fit.

Ski boot shell: Dalbello Lupo Pro HD Lower leg and foot volume: Low volume heel/ankle, high volume forefoot Skier type: hard charging, any trail in any condition. The heel hold in these liners is eye-opening. I've skied the stock liners once or twice since switching to Zipfits. I'd feel safer skiing Zipfit liners with my shells unbuckled than stock liners with the buckles cranked down. ~300 days on the liners and they ski better than ever.

Only have a day on these because the season ended, but wow! Pretty blown away for first day performance with no tweaks yet. Shell fit with the model you choose is important. I wound up ditching my worn out Mach 1 LV 130’s and tried a few different options( couldn’t get my foot in with LV’s and this liner). Wound up going to a wider shell, Lange RX 120 MV. Plenty stiff and feels like all of a 130 boot due to the liner and (presumably) the sidewinder construction. Conforms to my feet way better than my LV’s ever did, and without cranking the buckles down like worn out stock liners. Very impressed. I recommend Investing in a heated boot bag, or something,getting past the heel pocket is tough when cold, no issue with warm shells and liners. I prefer putting them on with the liners in the shells, try both ways.

Just received and while I have yet to ski in them I have worn the World Cups in my shells for around two hours. Fit is great and the heel locked in but comfortable. Looking forward to winter.

I have a 100 last foot using a 98 last boot. World cup took up too much volume. Changed to Corsa for a perfect fit. Really like the full leather liner in the Corsa - unparalleled grip in the heel pocket. I would give it 5 stars but the tongues are misaligned where they stitched to the liner - I expected perfection at this price.

I have been skiing in Zips for 20 years. I am currently in Lange Xt3 140 pro and Lange Rs 130s and the zips are interchangeable in them. These liners will stiffen up your boot slightly. The biggest plus of Zips is the absolutely locked down heel hold you can achieve with these. The Omi Fit material used can be added or subtracted from the ankle heel area on each side of your foot and also in the tongue. Once you get this dialed the performance of these liners is incredible, so much better than foam. The liners will also outlast several pairs of shells. I prefer to use them with a heated boot bag so they feel like putting on slippers every morning at the hill. All day comfort once dialed in.

Best line I have used - ever! This is my fourth Zipfit liner and the new World Cup is an outstanding model for performance skiing. The fit is so solid around the entire foot and ankle with the usual Zipfit comfort level as well. It took me a couple of visits with my bootfitter to get the set-up, but after that it has been smooth skiing for the entire season. My experience with Zipfit liners is that I will get 4-6 seasons in these liners - worth the wait on the order and the price.

I would add your review scale with a 7-8 at the upper end and rate the Sidewinder as an 8+. The contact between the foot and ankle and the boot is moe solid and consistent than I had experienced in the two Gara liners I had used in the past. The experience of high speed carved arcs in the Sidewinder on a FIS slalom ski is about as much fun as I have had in a very long time. The Sidewinder is the perfect liner for advanced skiers and ex-racers.

I had already owned an earlier Zipfit and loved it. It solved many boot fit issues and improved my skiing immeasurably. The World Cup, as recommended by Zipfit has been in another league entirely. The fit, of course, is excellent, but it's also taken the boot performance to another level. The Zipfit is so precise, that I sometimes think the boot shell is really just there to attach the liner to the skis. My last Zipfit lasted more than 500 days and was still going strong, but I'm delighted that I upgraded.

I’ve been trying to find the right liner and boot combination for years. I’ve skied stock, foam liners and now Zipfit and they are hands-down the best thing I’ve tried yet. If you want that locked in feel without sacrificing comfort this is the way to go. Yes they are expensive, but you will never buy another liner and they will outlast your shells. When it was time for new boots I simply moved the liners over to the new shells.

I have had the good luck to ski in these liners for the past ten seasons. Let me be more specific - I have skied ONE pair of these liners for the past ten seasons! That's well over 500 ski days in a single liner. These may seem like a steep investment, but when amortized out the value of these liners is a no brainer. All that penny pinching talk is to say NOTHING of the technical/performance superiority of my ZipFits. The edge control from the sidewinder is unmatched. My feet stay warm. The cork makes for the most comfortable boot setup I've ever skied. Not much more to say other than whenever (if-ever) my liners wear down I will be buying another pair with a smile on my face.

I have worked in the ski industry for 40 years. I have tried countless different boots and liners. I have a very narrow foot. Heal, and ankle area of my foot has never felt secure in a boot. The zipfit liner is definitely the best fit, as well as comfort I have ever felt in a boot.

Each contour of my foot is met for top shelf response and comfort. LOVE these!