You're looking for a 200ml snaplock. Shouldn't be difficult but PLEASE NOTE: THIS IS NOT A ROADSIDE CACHE. YOU WILL NEED TO APPROACH GZ FROM THE PLAYING FIELD SIDE.
It's part of a series of caches that will provide clues for the final which is based on a much-loved book.
There is no clue in the cache. To find the clue you need to look around you. What do you observe within a 25 metre radius of GZ? Perhaps you could note down what you see for future reference when solving the final puzzle.
Please re-hide as found.
And please, no spoilers about the puzzle in your log.