Bulletproof Braces Mouthguard: World’s Thinnest & Strongest Braces Mouth Guard for Sports. MMA 7v7 & Flag Football Lacrosse Basketball Hockey Rugby BJJ Boxing & Sleeping. Adult Youth Kids Mouth Piece is up for auction in Sports & Outdoors. The current bid is $5.50, 77% below the $23.90 MSRP, in New/Like New condition. This auction has ended — similar items appear in live auctions regularly.