Teeth: 40/42/44/46T/48T/50T/52T. Weight:40T 78g; 42T 89g; 44T 99g;46T 111g; 48T 124g; 50T 137g; 52T 151g. Narrow wide tooth profiling prevents chain drop. Compatible with: 8/9/10/11/12 speed chain. Positive tooth corresponding chian tooth width; tooth corresponding negative chain is narow.