LIETZ SURVEYING PRISM HOLDER ADAPTER TARGET EXTENSION. NOT SURE WHAT TO CALL IT BUT BEEN ON MY SURFEY SUPPLY SHELF FOR YEARS NOT SURE IF IT WAS EVER USED. ASK ALL QUESTIONS PRIOR TO BUYING. IT MEASURES APPROX 9” LONG AND TARGET IS 5.75”x2 7/8” HAS THE STANDARD THREAD USED BY SOKKIA AND TOPCON. TARGET ADJUSTE APPRIX 5.5” UP AND DOWN USING THE ADJUSTMENT KNOB