Screwgate HMS carabiner which is well adapted to work with your belay device.
It can be used comfortably with 2 ropes at a time, with little risk of the two strands overlapping each other during a fall.
The wide end has room for 2 ropes sliding side by side and does not generate any friction on the sides of the karabiner when the rope is loaded or when a leader’s fall is held.
Keylock system