Surprising detail in Lara Worthington's post as she poses for an impromptu photoshoot during holiday in Bali

Lara Worthington rarely puts a foot wrong when it comes to fashion.

And on Sunday, the Sydney-born model showed off her very expensive style during a holiday in Bali.

The 37-year-old carried a $4200 leather Prada bag as she posed for an impromptu photoshoot while exploring the city.

But fans pointed out another surprising detail in Lara's post - an Oura Ring on her right hand.

The smart ring is used to track sleep and physical activity as it contains an array of sensors that measure heart rate, respiration, body temperature and acceleration.

The model gave fans a glimpse of the ring as she posed on the street in a grey shirt and mini skirt.

Lara's trip to Bali comes after she enjoyed some down time with her family in Australia ahead of the Christmas holidays.

The model spent time in Darwin with her husband, Sam Worthington, and their three sons.

She posted to Instagram on Friday to share a candid glimpse at her vacation.

In one image, Sam, 48, held up a skull from what appeared to be a crocodile while one of their sons played in the background.

In another, Lara got up and personal with a croc while in another she shared the pub the family stopped at, called Shenanigans.

A final photo depicted the blonde aboard a boat and wearing a wind breaker and sunglasses.

In her caption she wrote: 'The new Irwins' referring to the family of Steve 'The Crocodile Hunter' Irwin who are known as for their love of crocodiles and wildlife. 

Sam and Lara began dating in 2013 and married secretly in 2014 and have since welcomed three sons - Racer, eight, River, four and Rocket, nine.

Earlier this month, Sam had an awkward run-in with a reporter on the red carpet of the GQ Men Of the Year Awards.

Channel Seven reporter Sally Bowery introduced Lara to viewers of the Sydney event by her maiden name Bingle - and it went down like a lead balloon.

'Her name is Lara Worthington,' the Avatar star clapped back.

'It's only been ten years,' a clearly irritated Sam quickly added.

Bowery quickly apologised for he faux pas.

'That was my slip,' she said.

Later on in the evening, the Avatar star was crowned GQ's Man of the Year.

Following the red carpet Bingle bungle, Sally clapped back at the actor in a column for Seven.

'I said Lara's maiden name. Not the wrong name. Just a name she had used for a big part of her life. One that was a household name, long before she met her husband,' Sally said.

She insisted Lara herself didn't seem 'the least bit bothered' by her slip-up and laughed it off as she shared her confusion about why Sam wanted her referred to by her married name.

Sally argued: 'So why then at an event celebrating what it now means to be a modern man didn't her husband? A married woman's identity is far more than her husband's surname.'

She then went on to cite Sam's own acceptance speech when he was crowned Man of The Year hours later, in which he spoke about the need to move past outdated notions.

'[He told] the crowd that men "can love others unconditionally and respectfully, without having to live up to some outdated standard or some stereotypical, archaic, and just plain sad idea of what a man should be".'

'I couldn't agree more,' she concluded.