1. Material: CR-V chrome vanadium steel 2. Specification: 17/19/21/22/23/24mm 3. Length: about 27 cm/piece 4. Single piece weight: about 400g for 17mm, about 450g for 19mm, about 500g for 21mm, about 530g for 22mm, about 560g for 23mm, about 600g for 24mm 5. Surface treatment: galvanized 6. Standard: metric 7. Features: non-slip texture, mirror texture, high material strength, good toughness, sturdiness and durability, anti-corrosion and not easy to rust, one end is a sleeve and the other is a batch, which is convenient and practical