This is a gorgeous vintage sequined maxi dress in from the 1980s. Made of white silk chiffon and lined in white silk habutai, it is covered in silver sequins and silver glass beads along the trim. It is in excellent unworn condition and there is only one tiny 1/2 inch line of sequins missing from one sleeve, this is shown in the last photo.

Designer: Mark & John by Sam, tag size XL. 

It is shown on a size 4 US dress form, not pinned. The measurements listed below were taken while dress was laying flat and doubled where appropriate. 

Bust - 44 inches
Waist - 36 inches
Hips - 44 inches
Length from shoulder to hem - 57.5 inches
Sleeve length - 11 inches
Sleeve opening - 16 inches