The M54 version of the Askar backfocus adjuster's front telescope interface is female thread M54x0.75 and the rear camera interface is male thread M54x0.75, the overall thickness is 18mm and offers ± 2mm adjustment range. The backfocus adjuster is CNC machined. Each unit is a 0.05mm precision adjustment, the surface is printed with a scale for easy adjustment and to save the position. There are two holes for fixing screws, which make the adjuster easy to use with different products. By rotating the backfocus adjuster, it can be adjusted between ±2mm to match the backfocus requirement, and to solve the various imaging problem caused by the backfocus. Users just need to choose according to their product's rear adapter. Specifications Front adapter： female M54*0.75 Rear adapter：male M54*0.75 Thickness: 18mm Adjustment range: +/- 2mm Minimum adjustment range:0.05mm per frame
