Back in middle school during lunch break I used to play basketball (God I hated it...) with my friends. I was never an "injury prone" kid by any means, but when I'd play basketball, like clockwork I'd jam two of my fingers (Usually index and middle digits) every few months.
I'd need to wear finger splints for about a week, and sweet buttery Jesus were they sweaty and itchy. Back then 3D printing was mainly for large industry, not really home use. Fast forward to today; I and many others have designed such medical devices to remedy the issue, along with keeping it cheap.
In short, this is a variation of my original Moldable Finger Splint; (https://www.myminifactory.com/object/3d-print-moldable-finger-splint-99482) designed for two fingers.
Like the previous version, the branching structure of the splint allows for air ventilation to the digits held in place. One half of the splint is slightly longer to accommodate for a longer digit like and index digit being splinted with a middle, a ring digit splinted to a middle, or a little digit splinted to a ring digit. The wrap-around strap on the longer side is set higher to accommodate higher skin webbing on said longer digits as well, to avoid pinching and general discomfort.
This can be scaled on the X and Y plane to custom fit whomever would use the device. To make use of the left hand, just flip the model over (The higher digit side should face the right side)