Looks and feels pretty realistic which is great aesthetically. It also functions decently well for play when the rod is inserted, my partner enjoyed it and the pressure it provides is nice. The cup is a little bit long for my anatomy, I have to tuck/hold the back closed otherwise it spills out the back because it extends beyond my perineum. So if you're a smaller human you may need a smaller STP.
Overall loved this harness! The strap meant to hold the balls of a standard non-STP packer is a little weird when using it for an STP, but overall it holds everything in place nicely. I sized down one size and while it does cut in a little bit, it keeps everything snug during my typically busy and active day.
The packer can look a bit big, almost transitioning from soft to hard dick, but I am a fairly skinny guy. Other then that it's a great packer. Very smooth silicone, easy and comfortable to wear and gives of a good illusion!! 10/10