A fantastic idea in theory - the tunnel is really long when extended, and the bunnies had lots of fun running through it. You can easily link the tunnels together. It's very light so they like to throw it around, although that's probably added fun for them!
However, because of the thin plastic, it's so easy for rabbits to chew - if they swallowed the pieces it could block/slow their gut, which could be fatal... I've also heard of rabbits cutting their mouths on the plastic fragments.
(Until SnuggleSafe rectify this, consider trying a builder's merchant or building site for pipe/cable ducting offcuts)