I have booked a flight to Pisa on Ryanair. their policy regarding strollers is as follows :

'one fully collapsible pushchair per child may be carried free of charge'

My question is what exactly they mean by collapsible pushchair ?

We have a stroller which when collapsed is in two pieces. 1. The wheels & base 2. the buggy type seat on which the baby sits or sleeps.

Is this kind of stroller allowed on ryanair ?

Or should we buy a one piece buggy ? Obviously I am not so inlcined now to invest in a new buggy.

Thanks in advance