Sinar extended macro tube lensboard with Copal 0 press shutter for use with large format macro.

Press shutter is self-cocking type useful for multiple exposures often needed to build up the exposure for macro where often exposure times are quite long or need multiple flash pops.

Shutter has a built in aperture which is working although redundant (would normally be set to the maximum opening because your macro lens will have an iris)

In good used condition, some signs of age and use but all working.