Decent quality Lambretta kickstart piston screw. This peg screws into the side of your kick-start piston and is engaged by the mechanism that pushes the piston out - The ramp secured to the chaincase side on series 1, 2 and 3 Lambrettas and the ramp that is part of the endplate on the GP/DL. 
 
This is quite a high wear item, especially on high compression motors, as it takes the brunt of the force when you kick-start your scooter.