A figure-8 blank (also called a Spectacle Blind Flange) is a pressure-retaining plate with one solid end and one open end connected with a web or tie bar.
Specifications:

Spectacle Blind Flange
Size: 1/2" to 60", DN 12mm to DN 1500mm
Pressure class: Class 150 to Class 2,500, PN 2.5 to PN 250
Facing: RF / RTJ
Material:
Cabon steel: A105, A350 LF2
Stainless steel: A182 F304/F304L/F316/F316L/F321
Alloy steel: F11, F12
Packing: plywood case and plywood pallet
Standards, Dimensions & Weight
ASME B16.48 Class 150
ASME B16.48 Class 300
ASME B16.48 Class 600
ASME B16.48 Class 900
ASME B16.48 Class 1500
ASME B16.48 Class 2500