1kg of natural and green pebbles.
Sterilised and safe to go straight in any indoor or outdoor enclosure. Perfect to use for any small or medium sized species. Keeping nails trim, keeping water cleaner and making climbing area's are just a few uses for this cheap versatile product. 
Can be reused over and over with just a rinse off in warm water should they get dirty.
These are a completely natural aggregate so shape, size and colour will vary massively between pebbles.
** Safety warning! **
Eating stones is a very common problem tortoise keepers face. If your tortoise does attempt to eat the stones and is able to get them in to their mouth then it is best to remove and increase the supplements they are receiving. In their wild habitat they would use grit and stones to supplement their diet and it is often a sign of need higher supplementation in captivity.