In this category you may find relays/solid relays and related products, like thermal coolers, thermal silicone grease, etc.
Solid relays are devices that turn on or off the power supplied to other devices. Generally, the relay operates as a physical switch. Relay is mechanical. Solid relay is fully automated and does not require human interaction, as it switches electronically. Relays/solid relays are used to control the appliances with low-current signals and high-current infrared sauna devices such as lights, chromotherapy panels, etc.
Solid relays are really durable and last for several millions of cycles. The internals of the relay are purely digital, so the mechanism is durable. Solid relays turn on and off really fast; usually this operation takes approximately 1ms.
Solid relays operate silently, as the switch inside solid relay does not suffer from contact bounce. Solid relay mechanism is almost unsusceptible to physical vibrations. As for the relays, they may emit quite click sounds.