the TST system has flow thru sensors and user replaceable batteries for the sensors...
I would not want to have to take off a sensor to top off a tire, nor would I want to purchase or send back a sensor merely because the battery was dead.
I have only had mine for about 2 weeks so I can't say anything about serviceability, but I bought the TST unit because of the sensors.
I bought from
and I am glad that I did. The site owner deciphered the normally badly translated owner's manual into two typed pages of ENGLISH that I followed during installation without a problem. 3 year warranty...