Made from polished 7075 military grade Aluminum, these are super durable replacements for this hard to find item. 

Size:
Length: 5265" - 11/32" - 13.36mm
Width: .3025" - 19/64" - 7.69mm 
Height: .1645" - 5/32" - 4.18mm

It uses a metric clamp screw linked below.