What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Ferrite beads are highly effective at suppressing unwanted high-frequency oscillations, known as parasitic oscillations, in the VHF and UHF ranges. When slipped over a wire, the ferrite bead acts as an RF choke that presents a high impedance to high-frequency signals while allowing lower-frequency HF signals and DC to pass with minimal loss. Electrolytic capacitors are used for low-frequency filtering or power supply decoupling, not for suppressing VHF/UHF parasitics at RF terminals. Steel-core toroids are unsuited for RF due to high eddy current losses, and Butterworth filters are complex multi-component networks, rather than simple component-level suppressors.