Open from 08:45 to 16:30. the Prarion brings you from Les Houches (1010m) to the Prarion plateau (1853m). Only the Prarion gondola will be free.
To ski the Les Houches resort you'll still need a Les Houches lift pass. Holders of the Mont Blanc Unlimited ski pass are entitled to use the Prarion gondola.
You just have to present your MBU pass at the ticket counter to receive a voucher.