S8291 astronomical telescope rear intercept adjustment king, astronomical camera deep space camera rear intercept ring after flat field

S8291 astronomical telescope rear intercept adjustment ring
 
Thickness ranging from 8-29mm, fine tuned in steps of 0.5
 
Reaching: M42, M48, M54 internal thread to M42, M48, M54 external thread, the entire set can achieve 9 types of ring connections and mutual conversion functions.