Just purchased and used the TST 507 TPMS with Flow Thru Sensors. It worked flawlessly on a 600 mile trip! I’ve read other reviews that indicated that the color screen was hard to read in the sun. I did not find any problems seeing the screen at all! I would also like to say that the Customer Service provided by Mobile Must Have is EXCELLENT! I tried to put in a discount code at checkout and was told the code was not valid. Made a note in the comments section about the invalid code and the very next day I was emailed that the discount code would be accepted and my credit card was credited the very same day! That’s the way to treat customers! I definitely recommend buying from this company!