It is screwed into a telephone pole, or possibly even a tree, and creates a step for someone to climb up. They would have to screw in several of them on their way up on each side, to hang phone lines. The little edge sticking up on the end is so your foot doesn't slip off. After screwing it into the pole, the angled piece pushes into the pole as you put weight on it, making it stable.
— 10 USD by Russian Post
— 25-40 USD by courier service EMS
— 30-40 USD by Russian Post
— 40-60 USD (depends on customer's country) by courier service EMS
What is the difference between Russian Post and EMS courier service? Read here - link