BMX (Tech 77) based lever with brake lock function.
Lever is pulled to activate brake and then thumb button pushed-in, which holds the lever open.
When the lever is pulled again, the thumb button will return via a spring.
 
Hinged clamp allows easy fitment as supplementary lever. 
Cable pull ratio is designed to work with Sidepull and Centre pull (non-V-brake) calipers.
Specification:
20mm Longer lever handle than Tech77 version (182S) lever
Diecast aluminum bracket, A6061 forged aluminum lever handle
Finish:Black bracket, Silver Lever handle
Thumb-lock stopper
Hinged clamp(φ22.2mm)
Weight:120g/pc