The SIMPLEX Shaft from BULLS are shafts which are made of aluminum and are very strong. These shafts are available in 5 sizes MEDIUM: Length 45mm, Weight 1.48 grams. IN BETWEEN: Length 39mm, Weight 1.3 grams. SHORT: Length 35mm, Weight 1.22 grams. X-SHORT: Length 32.5mm, Weight 1.23 grams. XX-SHORT: Length 12.5mm, Weight 0.72 grams. You can easily replace shafts with any dart. They are available in different sizes to customize your dart in length and feel. Sizes: XX-Short/Micro, X-Short, Short, In Between, Medium & Long. In addition, they also consist of different materials: nylon, carbon, plastic, metal, etc. In short, you can adjust your dart to your own taste and feeling through different types of shafts.