Kelly, whose real name is Colson Baker, explained how he worked with British jewellery designer Stephen Webster to create the engagement ring, which is actually made from two magnetic bands that interlock.
The rings feature two pear-cut stones, a diamond and an emerald, that form the shape of a heart when worn together.
In a close-up video of the rings on Fox’s finger posted to his Instagram account, Kelly said the ring was designed with the couple’s unique relationship in mind.
He wrote: “I know tradition is one ring, but I designed it with Stephen Webster to be two: the emerald (her birth stone) and the diamond (my birth stone) set on two magnetic bands of thorns that draw together as two halves of the same soul forming the obscure heart that is our love.”
Webster was appointed Member of the Order of the British Empire (MBE) in 2013 for services to training and skills in the British jewellery industry.
His jewellery is popular among celebrities and has been seen on the likes of Madonna, Cate Blanchett, Dua Lipa, Taylor Swift, Kylie Minogue, Olly Alexander, and others.
Kelly and Fox became engaged on Wednesday after a year and a half of dating, during which they have appeared on numerous red carpets, in interviews and photoshoots together.
Fox posted a video of the proposal, which took place under a banyan tree they both sat under in July 2020 to ask “for magic”, she said.
“We were oblivious to the pain we would face together in such a short, frenetic period of time. Unaware of the work and sacrifices the relationship would require from us but intoxicated off the love. And the karma.
“Somehow a year and a half later, having walked through hell together and having laughed more than I ever imagined possible, he asked me to marry him,” Fox continued.
“And just as in every lifetime before this one, and as in every lifetime that will follow it, I said yes. And then we drank each other’s blood 1.11.22.”
Fox and Kelly met on the set of the movie Midnight in the Switchgrass in May 2020. The Transformers star was previously married to Brian Austin Green, but the pair split up in May 2020 and Fox filed for divorce six months later.
She shares three children with Green, Journey, five, Bodhi, seven, and Norah, eight.