Jock Strap: Envy
This is a pretty simple yet very well-made jock strap to keep your packer in. Made of 95% Cotton, 5% Spandex, this is very comfortable against your skin and has a really soft waistband.
These jockstraps do not have any openings in the front, so they would not be a great option for using with an STP.
S/M = 28-32"
M/L = 32"-36"
Images courtesy of Envy