F3, meaning "formula 3," is a multi-layers packer, with multiple silicone outer layers with softer and tackier inner layering. F3OG has a dual density squish, with f3+ having a slightly harder "core" when squished. To get an idea for the feel, squeeze your T dick -- it has a harder "core" in it also!
Basic packers are "single pours." Our basic plus line is a super soft single pour that granny paints with a less tacky silicone so you get a packer that is cheaper, softer, and cozier than any other basic packer on the market.
STPs are single pours with a hole through the shaft. You can get a formula 3 scrote and suspended testes for a few extra bucks!