ditto to Dutch
TST caps, without the security shell. Easy to do, just remove two little screws
I'll add that I'm pretty sure all these brands use the same sensors...maybe different frequency or electronics maybe, but functionally the same so for questions regarding which style I'm pretty sure you'll get the same experience as us
I originally bought the flow through cells and installed them on the valve extenders, but have slowly changed all but two of them out to the buttons.
Had lots of problems with the extenders and the transmitter. SOmetimes the transmitter wouldn't engage the little push rod to let the air out of the tires, and sometimes I think the push rod was extending out too far and sorta damaged the transmitters. All of them are teh same in this regard.
Over time I had a few transmitters with their original batteries leak inside and corrode, some looked like water might have gotten in, and some were replaced because of apparent damage form the extenders. I tried a couple different kinds of extenders. I often had to remove teh flow throughs to get air into the tires, then when putting them back on I'd see some of these problems and even some failures.
I'm slow I guess, so it took me a long time to smarten up and just remove the wheel simulators for good so i could get my hand in, then trashed the extenders. Also, you really only need to air up occasionally anyway, so there's little need for the flow through in my opinion.
Also, I have the system with the user replaceable batteries. I remove my sensors when in storage, and we're only using the RV occasionally so I install them before trips. I've had to replace batteries more than it seems like I should have. It's easy but also a pain in the neck in one way because you often have to replace the o-ring & I have yet to find a local easy source to get them....small and odd size.
So
I have often wondered if I would have been better off with the factory replaceable battery system with batteries that supposedly last a lot longer.... I just don't know....