Features and Benefits: Sixth Ball shows overprotection with rugged safety shield; Thexton's professional model and the most popular Cold-Chekr; The 102 has a rugged, chrome plated safety shield of ABS plastic; Also used to test Dex-Coolr; Comes with vinyl case imprinted with instructions; Accurate to -34 degrees F, indicating optimal 50/50 mixture Special 6th disc shows overprotection and loss of cooling protection Ideal for garage or service station Bulb and long dip tube makes this tester fast and easy to use.