1. Passive SL buccal tubes, upper clip open towards occlusal, lower towards gingival
2. Mesial-distal extension design for lower occlusal ligating wings, so as to prevent bite conflict
3. Fixed hooks far from the gingival, to ovid gingival irritation
4. Patented clip design, Clip works smoothly
5. 80# mesh base, lower profile, compact and smooth surface
6. Non-convertiable tube for 1st molar, more easy and high efficiency for wire replacment