Check out these daring doggies! One hundred years after police started using dogs to help them tackle crime, a series of stamps has been launched to pay tribute to the work done by man's best friend.
Fighting crime, saving lives and just helping people out are part of the daily work of thousands of the UK's working dogs.
Police dog Max has been honoured with a stamp, along with mountain rescue dogs, sheepdogs and guide dogs.
Max and his canine colleagues help catch criminals, sniff out evidence, and keep large crowds under control.
Assistance dogs have been specially trained to help people out by opening doors, switching on lights and posting letters.
This is the first time a set of stamps has been devoted to the UK's "secret army" of four-legged friends.