90MM guide star ring with height increasing block, two sets and one pair

B212 90mm Six point Navigation Ring (Two in One Pair)
Thickness: 8mm, maximum diameter of guiding mirror: 80mm, minimum diameter of guiding mirror: 45mm
Material: Aluminum alloy
Ring weight: 135 * x=270g
Number: B/S7931
Upper edge
Length: 48MM Width: 23MM Slot Width: 16MM Slot Depth: 1.5MM Bottom Edge
Length: 56MM Width: 30MM
Height of cushion block: 18MM Weight: 50g/block