James has been a volunteer firefighter for almost five years while Michael has been doing it for eight.
Jordan and Daniel say they've "been around it since we were toddlers", as they come from a family of firefighters.
Their grandfather Kevin, who died in 2016, was a firefighter for about 26 years, their father Hamish is one.
Hamish has two brothers, Tony and Mark who are in the Hastings brigade, along with Tony's son Matthew.
Jordan joined three years ago and Daniel almost 18 months ago.
They're both looking forward to doing the challenge, because they feel it is to support a good cause.
James has extra motivation - he's doing it in honour of a little girl who passed away from leukaemia.
Chloe Mullally was just three months shy of her third birthday when she died.
Her parents, Paul and Joey, who had come to New Zealand from Ireland a few years earlier, had posted about Chloe's battle on Facebook.
"I just randomly saw the post on Facebook and messaged [them]," James says.
He says they were a little hesitant but happy that James wanted to do the challenge in honour of Chloe.
"I couldn't imagine anything worse. I've got a young fella myself and I don't know what I'd do if I didn't have him."
Firefighters from all around New Zealand will be taking part in the challenge in May, but it's not about competition.
"Everybody's cheering everybody on," Michael says.
Each firefighter has to enter the building and go down to the basement to start the challenge.
"Everybody stands there and cheers at you," James adds.
And at the end of the day, they're all firefighters raising money for the same cause.
While they would like to say they've been training hard for the challenge, Michael admits it hasn't worked out that way in the past.
"We always tell ourselves we're going to do some training, but it never happens."
This year, as part of their fundraising, they have been doing various jobs like hay stacking, which might help in their training.
They will also be looking for other ways to raise money, such as having a bucket for donations outside a local shop.
Last year, the Cuba St Bakehouse in Palmerston North helped them with a pie fundraiser.
The team also have pages on the Sky Tower Challenge website where people can make donations, which they are very thankful for.
Whatever the donation, whether it's $2 or $200, every little bit helps.
Donations can be made via their page: https://firefighterschallenge.org.nz/t/dannevirkevolunteer.
