Features:
1. Transparent chest wall and made of special material, perspective effect of bilateral venous channel;
2. Correct anatomical position: basilic vein, cephalic vein, jugular vein, subclavian vein and superior vena;
3. Direct observation of rib and heart, measure the correct inserted length of catheter;
4. Transparent part of the superior vena and visible of the ductal position in the case of correct catheterization, or the catheter is invisible;
5. Exercise of standard venous catheterization position;