Disc-type tester with plastic body and rubber bulb. Freeze protection level indicated by 6 x floating coloured discs. Easy-to-read temperature table. For determining levels of ethylene glycol anti-freeze. Disc-type tester with plastic body and rubber bulb. Freeze protection level indicated by 6 x floating coloured discs. Easy-to-read temperature table. For determining levels of ethylene glycol anti-freeze.