Perfect for backdoor training and re-training! For those new to anal play or experienced pros - graduating glass plugs make it easy! Work pelvic floor muscles for better control. strength and endurance during sex. Start small. move to medium. then take on large with sensual ease! Warm or chill plugs for even more thrills. Made from durable. tempered borosilicate glass. Dimensions:Small: 4.55 x 1.15 in.Medium: 5 x 1.35 in.Large: 5.75 x 1.5 in.