This is a radiator coolant overflow hose with cap for a Toyota Land Cruiser FJ40. Fits model years 1978 - 1984.
Part # 16405-60031. This is the latest iteration of the cap that appeared in the final years of FJ40 production. Perfect complement to the OEM Coolant Overflow and Windshield Washer Bottles.
Can also substitute for the discontinued FJ60 cap and hose, 16405-90A03. However, the hose to the radiator cap will be short by a few inches. Either replace with a longer hose or re-use the original one.