Carbon-linked tetrahydro-pyrazolo-pyridine compounds are described, which are useful as cathepsin S modulators. The drive arm may be made of a pull-molded composite material having a relatively low modulus of elasticity and a relatively high elongation factor. Consequently, the solenoid air valve structured such that an area of magnetic pole is sufficiently ensured even if the moving core is made thinner in order to ensure a volume of a coil body in reducing the solenoid air valve in size can be provided.