Form Function's handmade products feature a flexible but sturdy design, and have impressed us with their user-friendliness. That being said, we would still strongly suggest practicing peeing with a STP before using outside of safer spaces, since having an unruly prosthetic can be a severe safety issue.
The Model A features a larger design than the Model D Sport - although their reservoirs appear to be the same. Designed to be worn with the Form Function Slingshot Harness, this packer fits up snugly against the urethral area for the purposes of peeing while standing. Made of silicone. 3 1/2" x 1 3/8"