BD Ascender´s do the job !!!
These ascenders are great they slip very well on the rope, work on ropes from 8 to 13 mm, are light weight and ergonomic, and the switch is just simple and easy to operate, the only problem that i see is if you take a very strong fall the little teeth could really harm your rope, not really sure but it could happen, but right now these are just the best !!