Boao 20 Pieces Presta Valve Core Bike Replacement Brass Tubeless Core for Tubeless Road MTB Bike, Stan's, Vittoria, Continental, Kenda and Mor

So much junk for sale, gets confusing. You don't know which reviews are bought or bots (pun intended). I am a gravel, road and mtber from the US. A real customer. Just had to get that out there.My wheels use valve stems from Muc-Off, Stan's, American Classic, etc. Read some other reviews about overall length being not long enough for this brand and the other Chinese copycats. All that said, this product works perfectly in all my presta stems. Don't be cheap and quit fighting your clogged presta cores. One day/ride you will have to deal with the clogging issue in the middle of nowhere, and your CO2 and mini pump will be fighting the sealant and air pressure. I don't know if $9 USD delivered for 20 is a screaming deal, but how much is your time and frustration worth when unable to put just enough air in a tire - in the middle of nowhere when it's scorching hot or freezing cold - to get home? Yeah, that was me yesterday. These core replacements were ordered after pedaling squares slowly for hours, and minutes after Amazon delivered the tiny sealed bag they were installed in every bike.This seller does not include the (blue) valve stem core remover tool, but I'm guessing most "serious" cyclists have one already or they use a small needle nose plier.

Bought for my MTB. No issues or problems with installation or leakage. Good quality for the money.

They fit and work, that's all I need them to do. I have several MTBs that are all tubeless. Presta valves get clogged and sticky if not aired up often. These are so cheap it's not worth cleaning the clogged ones. I keep a couple in my trail bag just in case.

They get the job done, but it's definitely not a high quality product. If you unscrew these too hard, the little end knob will fully come off, which is annoying. But it's good to have a cheap supply of valve stems at the ready.

Does what they are supposed to. No issues.

I've only used one of these so far but it works great on my tubeless gravel bike. Haven't had the problems that some reviewers have experienced. Hopefully the other 19 work as well. Can't beat the price if they do!

Was looking for Presta style valves to replace other ones that were bent. These fit the bill and have met all of my expectations: cheap easy to install, and work very well. Would buy again. Cons: none

Necessary if you’re running tubeless. Just tried to air up a tire and couldn’t get the air in. It was nice to have these on hand for a quick replacement. The little tool that comes with them works perfectly.