This is the Hop-Up Option Touring Car Spring Set (Short Type) from Tamiya.
This will work for the 1/10th scale cars from Tamiya.
FEATURES:
Three tensions to the spring set either Soft, Medium, or Stiff springs.
Steel construction
INCLUDES:
Two red neon soft springs
Two yellow neon medium springs
Two blue neon stiff springs
SPECS:
Length: 23mm (0.92")
Diameter: 16mm (0.62")