Gunson Anti-Freeze and Coolant Tester 77105
The Gunson is unique in having a dial gauge.
The Gunson is unique in having a dial gauge, which allows you to get a more accurate picture of your coolant protection than some all-or-nothing rivals.
It works by drawing the mix in, but you have to get it pointing upright before you read off the result.
You’ll need to remove air bubbles, although it’s pretty accurate with both types of coolant, plus is easy on the pocket.