The Solo Loop Apple Watch band was released in 2020 along with the Apple Watch Series 6. The packaging describes this product as a “Silicone Fitted Band.” According to Apple’s website:
“Made from liquid silicone rubber, the Solo Loop features a unique, stretchable design with no clasps, buckles, or overlapping parts that’s ultracomfortable to wear and easy to slip on and off your wrist. Each band is specially treated with UV to give the band a silky, smooth finish. It’s also swim proof and sweat proof so it can go just about anywhere you want to wear it.”
This band is Cyprus Green, a shade of dark green. It was available in 40 mm and 44 mm widths, and was among the first Apple Watch bands to be sold in specific wrist sizes. The 40 mm Solo Loop was sold in wrist sizes 1–9 and the 44 mm Solo Loop was sold in wrist sizes 4–12.
According to Apple’s website, “This band comes in custom sizes because it’s designed for an ultracomfortable fit. An accurate measurement will help you get the size that’s right for you.” The website allowed buyers to download a PDF and cut out a “tool” that wrapped around the wrist to designate the band size needed.
This snug-fitting design allowed Apple Watch sensors to retain constant and consistent skin contact, allowing accurate blood oxygen and heart rate measurements to be maintained.