Moulding it. Fill a bowl with water at 60–65 °C (hot tap water plus a splash from the kettle; not boiling). Hold the splint under for 60–90 seconds until it goes soft and floppy. Shake it off, lay it on a sock or a thin sleeve on the inside of your forearm with the notch at the thumb, and wrap it round with your other hand, holding the wrist straight or a touch back. It stiffens in about a minute; run it under the cold tap to finish. Thread the straps through the slots. If the shape isn't right, warm it again and try again — as many times as you like.
How it is made. 2.4 mm PLA, the pattern covering just over half the way round so the straps close it. Six-millimetre holes on an 11 mm pitch through the forearm and wrist, none across the palm bar. Three pairs of slots for 25 mm hook-and-loop straps — three straps come in the box. The preview shows it twice: flat, as it prints, and curved, as it sits once moulded.
Please read. This is a printed support you shape yourself, for comfort and rest. It is not a medical device, it is not fitted by a clinician, and it is not for fractures, sprains, numbness or anything that swells or clicks — see a professional for those. Take it off if it rubs, and never sleep in a strap that is tight.
Sizes. Short, 190 mm to mid forearm, $34. Long, 240 mm, two thirds up the forearm, $42. Straps included.