Tyre

"A round portion of galvanised rubber. Required to repair the Camper Van."

Tyres are an item in Sheltered.

Obtaining
Usually, Tyres can be found in Petrol Stations, Shacks and Scrapyards, although the latter have a higher chance to contain Tyres and other RV parts.

Use
As implied in the description, Tyres are used in order to repair the Camper van. You will need four Tyres to fix the RV.