These brass with chrome plating urethral sounds are flat on one end for easy gripping with the fingers or perhaps attaching an electrode for electrical play. Originally used in the medical profession for dialating the cervix, they were also used to clear blockages in the urethra. Graduated sizes enable you to obtain the perfect fit. They range in insertable length between 5 1/4 to 5 1/2 inches and the largest width/diameter measures a full 2 inches. This deluxe 14 piece kit comes in a velvet lined blue leather case. This kit is a favorite due to its many different sized sounds.