Hi, i have started using this string 3 days ago. It is called Forten Titanium 65, with a diameter of 0.65mm. It is Pre-Stretched to reduce tension loss and ultra-thin to maximise power. I strung it on my AT-800 Defensive a week ago @ 28lbs, and now, it is still holding its tension excellently well @28-27lbs. I am a hard hitter and despite stringing @ 28lbs, and at 0.65mm, the string does not wear off or breaks. I can smash with tremendous power, even more powerful than BG 66 and NBG 98, and control where to place my shuttle. Loud "PARP" sound when lobbing and smashing the shuttle. Just requires more precision and skills in defending. Here is the string Conclusion Power: 9.5/10 Control: 9/10 Durability: 9.5/10 Feel: 9.5/10 Defense: 8.5/10 Recommended Tension: 24lbs-28lbs Highly recommended by me