GRINDER Ball Stretcher is made of heavy thick rubbery silicone...the heaviest and softest Ball Stretcher we make...the extra weight helps your nuts hang low...but this fucker is so soft and squishy your balls arent gonna feel too much squeeze...We made this bad-boy thicker in the middle to push your balls down low, the thicker middle keeps your nuts from popping back up and outand with 2 sizes GRINDER keeps even high-tight shy-balls low in their bagthe added weight of the thick silicone puts extra pressure at the top of your nuts just where you want it and feel it...The GRINDER-2 large size is for medium balls in a bigger size sack and huge nuts in a low-hanging bag...GRINDER-1 is for roid-balls, high and tight sacks, and medium balls stuffed in small bags...Silicone is the only material that will not irritate your sack, warms up and stays warm, and feels kinda like skin...we invented the silicone Ball Stretcher and keep making em better and better...Advice from Ox Balls, (we know a lot about ball-stretching): warm up your lube, warm up the Ball Stretcher by putting under hot water for a bit, because a cold chill on your nuts makes em wanna suck up inside you...if you have a high and tight sack, put your Ball Stretcher on in a warm shower or tub after your sack relaxes...and use a little lube on the inside the toy, that way as your sack relaxes the stretcher can slide and adjustFeatures - Pure Platinum Cure Silicone - Lube safe: water-base, oil base, water/silicone hybrid, silicone lubes - Cleaning: always clean any stretchy toys after use, they will last longer...use detergent and hot water, or put in dishwasher.Size Best for normal to small balls Total Height: 1.5/3.5cm Inside diameter: 1 1/8/3cm Outside diameter: 2.25/5.5cm