These free trials are normally limited to 30 days.
Brad's Deals Editor Michael,
First-time subscribers can get three free months of Audible Premium Plus along with three free months of Amazon Music Unlimited through this extended trial offer at Amazon. Normally, an Audible Premium Plus subscription would cost $14.95 per month, and an Amazon Music Unlimited would cost $9.99 ($7.99 for Prime members). So in total, this offer saves you $75. The normal monthly fees will apply to each subscription after the three months are up, but you can cancel at any time. There is no sales tax.