Most people following the smart ring space had the Oura Ring 5 penciled in for sometime in 2027. That timeline just got blown up. Oura announced the Oura Ring 5 yesterday, and it’s already available for pre-order with shipping starting June 4. The headline change is size. Oura says the Ring 5 is 40% smaller than the Ring 4 , measuring just 6.09mm wide and 2.28mm thick. The smallest sizes start at 2 grams. To pull that off, Oura rebuilt basically everything inside, including the mechanical, electrical, optical, battery, and sensing systems. The sensing hardware got overhauled too. Twelve signal pathways replace the previous 18, but Oura swapped in more powerful LEDs and redesigned sensor domes for better skin contact. The company says this actually improves accuracy across more finger types and skin tones, not just in typical conditions. Battery life nudges up to six to nine days, compared to five to eight on the Ring 4.…