How do Subscription Trials work? Can someone enligh me..?

[BlueCityMktg]

Hi Everyone, 

I was wondering if someone can help me understand the subscription button.

Here's my situation : I have a button that's set to bill the client after the a 30 day trial, but since I only want to bill the client once I only want to charge them once after that trial period.

Here's my dilemma : When I test the button, here is what I get for the Terms (picture below)

So now I'm trying to figure out... is the 30 days of trial part of the 2 installments?? or will the client be billed the amount twice after the trial period?? (the writing does bring confusion, and I certainly wouldn't want that to turn away my customers)

I've been searching all over the paypal community and the knowledge database without a definite answer.

If they are going to be billed twice, then we should have the option to only setup one (1) installment instead of the minimum two (2) when creating the button. 

Any help from the Paypal Community or Paypal Support would be appreciated to answer this question.