This is a night cache which is only discoverable with a Blacklight Torch.
You can find these on Ebay or other online shops for around £5 or less (at the time of writing). They take a couple of AA batteries. It is important to get the genuine 'blacklight' as LED UV torches will not show the clues to this cache as well. the real thing looks like a mini fluorescent tube that, not surprisingly, is black.
The co-ordinates give you a starting point, from where you will need to use your blacklight to follow the glowing clues to the cache location. The glowing clues will not show up in daylight, even with a blacklight, so you need it to be really dark before you start.
The end cache is a clip top box with some tradeables in and a prize for FTF.
The cache start is located down a public road, but this is not maintained by the Local Authority, so go slowly on the way down there,as there are quite a few potholes! The cache is not near houses, but please respect the neighbourhood. The 4 rating is due to the fact that you need specialist equipment to find. If you have the equipment, it should be a fun 1!