Easily Explore Anal Sex With This Sinclair Institute Select Anal Silicone Explorers 3-Piece Set. If you've always wanted to try anal sex, or even if you're an experienced anal adventurer, you'll love this 3-piece set of finger rimmers. The Sinclair Institute Select Silicone Explorers are progressively sized to get you started, and keep you fascinated. The set features 3 sizes of anal plugs all in one kit that stretch to fit your finger. These also are great for prostate stimulation. They are made of hygienic silicone; they're waterproof and easy to clean.