Rabbit Chew Toys

I have a rabbit 7 weeks old and want to start giving him boxes or tubes to cure his boredem! I am concerned, it is a bit too young and his stomach is too delicate for him to digest Incase cardboard, he swallows. What age do you recommend to start giving him?

7 weeks fine! Rabbits can digest it pretty easily.
If you still feel uncomfortable about it, the rabbits also like plastic baby keys to throw around. My rabbit likes banging against the walls of his cage =)