These are replacement Hop-Up springs for the Tamiya 1/10 R/C 4WD/FWD drive touring & rally cars such as the following: Could be more in the feature

Toyota Celica GT- Four Rally
Skyline GT-R Nismo
Mercedes Benz 190 EVOII AMG
Schnitzer BMW M3

FEATURES: Neon Red (2 Soft Springs) Springs are made of different
Neon Yellow (2 Medium Springs) wire composites
Neon Blue (2 Stiff Springs)

SPECS: Each spring is .052" thickness
1.10" length
.636" Outer Diameter
.526" Inner Diameter