These are Vertical Fins for the UL-1 Superior from AquaCraft.
Available in White, Yellow, Red or Orange.

INCLUDES: Two vertical turn fins

SPECS:
Length at Base: 3" (76.2mm)
Length at Top: 1.5" 38.1mm)
Width at Base: .75" (19.05mm)
Width at Top: .2" (5mm)
Height: 3" (76.2mm)