Anti-Peck bits are used to help as a short term solution to feather pecking in chickens.
You will need a pair of circlip pliers to fit these (available from the electrical secion of DIY stores). Please fit them very carefully as if incorrectly fitted they will be painful.
It is essential that the chickens have a very deep bowl of food and water when fitted with a Bumpa Bit as they have to 'scoop' it up from underneath rather than peck it from above.
Leave on for no more than a couple of months to try and break the feather pecking habit.
Small is suitable for smaller hens such as Pekins or medium sized hens as a first option.
Large are suitable for medium - large hens but are very intrusive so it is better to try the small size first (and re-fit a large if the small fails to work).