Dust protectors for 1/4" Hydraulic Quick couplers - like those found on many John Deere Subcompact and Compact tractors and Front End Loaders (1025R, 2025, 2038, 3R, 4R etc.)
Made for 1/4" ISO 5675 - aka "Ag" style couplers.
Store these in your Toolbox when not in use.
The stock dust covers are 'dangly' and tend to get caught on things and go missing. Another approach is using color coded zip ties to mark the connections and keep the dust covers safe in a toolbox when not in use.
Oil, UV and temperature stable materials