"In short, Andy actually walked into a sports shop and bought a Yonex Ezone 100. He also bought a Karakal grip, which is what he has used for a long time and a roll of lead tape. The lead tape is important as Andy plays with very heavy racquets and the retail Yonex Ezone 100 is relatively light at 300 grams unstrung.
According to sources, Andy added 30 grams of lead tape to the head of his Ezone 100. I own his personal PT57A racquet and I can confirm it is a heavy one at 372 swing weight strung. (...)
He strings it with natural gut in the mains at 27.5 kg (60.5 lbs approx) and a dark poly in the crosses. For a while he used Poly Tour Strike, but now, the last I heard, he is using Babolat RPM Rough in the crosses."
Source : Tennisnerd (je ne sais pas ce que ça vaut)