This deluxe kit is great for someone looking to into sounding play for the first time and great for urethral play enthusiasts as well. These sounds are different from other sounds because of the one flat end. The flat end is most commonly used to provide a better grip.
More advanced users may use it to hook up to an electrode for electro-sex play. 
This sound kit comes with 7 sounds ranging from 4 mm to 10 mm in diameter. 
Each sound is 19.3 cm/7.6" long with 13.5 cm/5.3" of insertable length. 
These sounds are slightly curved and are made from chrome-plated brass. 

Colour: Silver
Material: Stainless Steel
Package: Bag
Length: 19.3 cm/7.6 inches
Insert Length: 13.5 cm/5.3 inches

Max Dia:
0.4 cm/0.16 inches
0.5 cm/0.2 inches
0.6 cm/0.24 inches
0.7 cm/0.28 inches
0.8 cm/0.32 inches
0.9 cm/0.35 inches
1.0 cm/0.39 inches

7 Piece Deluxe Flat Ended Urethral Sounding Kit