Coma correctors, field flatteners and focal reducers require that the camera sensor be positioned at the perfect distance from these lenses.

The M48 Astroworx shims are used to precisely adjust this distance: each ring is made of stainless steel and can be inserted over each M48 male thread. They are also useful when the M48 threads are too long and need to be shorter.

Specifications:

• Inside Diameter: 48.1mm
• Outside Diameter: 60mm
• Available Ring Thickness: 0.2mm | 0.5mm | 1.0mm