Vixen, Magic, Neo, Uni are a series of incredible inflatable canine dildos produced by Elipse Art.

The Neo knot is soft and about the size of a golf ball. It grows to the size of a tennis ball (with about 7 pumps) or larger and is easily controlled. The shaft also expands slightly resembling the natural growth of the canine penis. The length also increases about 1 to 1.5" when inflated.
Size(uninflated):

• length(total): 6.25" (15 cm)
• length(usable): 5" (13 cm)
• length(tip to knot): 2" (5 cm)
• diameter(shaft): 1.25" (3 cm)
• circumfence(shaft) 4" (10 cm)
• diameter(oval knot): 1.8" (4.5 cm)
• circumfence(knot): 5.5" (14 cm)