Rocker Pete Wentz, who welcomed his second son Saint Lazslo last month, feels that he is an expert at changing nappies.

The Fall Out Boy rocker and his girlfriend Meagan Camper's son was born Aug 20.

"I'm a great diaper changer. There are a lot of things that go into it. Speed is a big part of it," People.com quoted 35-year-old as saying. He also has five-year-old son Bronx with his ex-wife Ashlee Simpson.

As for his duty as a father the second time around, Wentz says he's prepared for what lies ahead.

“I know the phases now, I know that they change and you are on the roller coaster and there are ups and downs and you're not falling off the ride,` he said.