Yonex BG66 Ultimax is a thin, high-repulsion badminton string designed for players chasing more power and spin off the racquet. At 0.65mm, it's a slimmer gauge than most all-round strings, which lets it bite into the shuttle more for extra spin and a crisper, more responsive feel — the tradeoff is that thinner strings generally wear and break faster than thicker ones, especially under hard, repeated impact. It's best suited to intermediate and advanced players who restring often and prioritize touch and control over sheer durability. Each order includes a 10m set / reel, enough for one full stringing job, and it's available in multiple colors.