RIO developed the T series as a tungsten alternative to lead because T series contains no lead. It is supple, does not kink. 30' Shooting Heads comes with Welded Loops Both Ends (NO LOOPS on T-20) T-8 8grains per foot sink rate 6-7ips T-11 11grains per foot sink rate 7-8ips T-14 14grains per foot sink rate 8-9ips T-17 17grains per foot sink rate 9-10ips T-20 20grains per foot sink rate 10+ips Vendor: RIO