Britney Spears Engagement Ring Details: Singer Receives 'One Of A Kind' Sparkler

Britney Spears and Sam Asghari are engaged after five years of dating.

On Sunday, the "Toxic" singer, 39, shared the happy news on Instagram, writing, "I can't f--king believe it." Alongside her message, Spears posted a video that captured her gorgeous round-cut engagement ring.

"Look at that. Do you like it?" Asghari asked Spears in the video, to which she replied, "Yes!"

Asghari also posted about their engagement on his Instagram, sharing a photo in which Spears flashed her ring in the foreground while the couple kissed in the background.

Asghari's talent manager, Brandon Cohen of BAC Talent, also confirmed the engagement news, telling Page Six, "The couple made their long-standing relationship official today and are deeply touched by the support, dedication and love expressed to them."

Asghari worked with Forever Diamonds NY founder and master jeweler Roman Malayev to create the custom ring for the pop superstar, E! News reported.

Sources told Page Six that the "one-of-a-kind" sparkler features a 4-carat round brilliant stone in a platinum cathedral setting and is enhanced with a floating solitaire design. The ring also has pavé detailing on the bridge and flush set diamonds on the prongs and basket.

To make it even more special, the 27-year-old fitness trainer had his personal nickname for Spears, "Lioness," engraved inside the band.

"Every designer I spoke with about the ring was amazing with great ideas, but I just clicked with Roman — we really connected on the design and he was as excited as I was to make it special — that’s why I chose him," Asghari said in a statement to Page Six.

Malayev told the outlet that he and his company "couldn’t feel more honored to create this ring for such a special couple."

"Their journey together has touched people around the world and we’re so excited to be a part of their forever," he added. "We are thrilled to congratulate Britney and Sam on their recent engagement."

Forever Diamonds NY is honoring the couple's engagement by naming the design, "The Britney."

Prior to the couple's announcement, an unnamed insider told Page Six that Asghari wanted to spoil Spears with a "very special, over-the-top and meaningful proposal."

"He dreams of one day becoming a dad too, and Britney, of course, has always wanted to have more kids, especially now that hers are getting older," the source said.