[replacement]:directly replaces your worn,cracked,broken,and unusable rail bar mounting plate [simple installation]:telescope dovetail mounting plate,easy to replace and install within seconds,no complicated tools needed [material]:the dovetail mounting fixing plate is made of premium aluminum alloy material,wear resistant,and has good performance [product size]:the telescope dovetail mounting plate size is 33.5 cm x 4 cm/13.19 inch x 1.57 inch [multiuse]:this dovetail plate can be used to astronomical telescopes,connect to other equipment to use,professional and practical