The 9743-M Quasi-kinematic, Quick-release Rail Carrier has a spring-loaded lever that allows it to be locked in place without introducing motion. An M4 screw permanently locks the carriers. Model 9743-M has two M4 counterbored and two M4 threaded holes and is 25.4-mm long. It works with 9731 or 9732 optical rails.
 

Quick-Release Optical Rail System

• Quick-Release lockable rail carriers for single-handed adjustment

• Large, readable metric and English scales

• Generous mounting hole pattern

This unique New Focus brand optical rail system combines an exceptionally light-weight rail with the ultimate convenience of quick release carriers. The rail uses an enhanced box-beam cross section to reduce weight without sacrificing stiffness.  The carriers, which are available in three different types, have a spring-loaded lever enabling one-handed lock and release operation. An 8-32 (M4) screw permanently locks the carriers in place. The rails are attached to the optical table with table clamps so that virtually any position or orientation is possible.  For your convenience, there are both metric and English scales on each rail.

Model  9743  optical rail carrier showing quick-release leverModel  9732 , showing English and metric scale