Elesa+Ganter GN 721.1 lever indexing plunger. Steel.

Used when the plunger must be retracted quickly. 
By rotating the lifting lever by 180°, the plunger stops in the retracted position. The lever is kept in this position by a notch.
Available in different types:

Type RA: Right-hand lock
Type RB: Right-hand lock, with plastic cover
Type RAK: Right-hand lock, with lock nut
Type RBK: Right-hand lock, with plastic cover, with lock nut
Type LA: Left-hand lock
Type LB: Left-hand lock, with plastic cover
Type LAK: Left-hand lock, with lock nut
Type LBK: Left-hand lock, with plastic cover, with lock nut

For materials please see datasheet under Documents.