These are nice compact boards for controlling devices that require higher loads (lights, heaters, solenoids, etc.) with TTL-level signals.  The relays on these boards can handle loads up to 1A (AC or DC) and have normally open contacts.  They are powered with 12VDC and require 1 TTL signal per relay.  They are available in the following versions:

	1 Relay TTL-Driven Relay Board: $10.50
	2 Relay TTL-Driven Relay Board: $21.00
	4 Relay TTL-Driven Relay Board: $39.25
	8 Relay TTL-Driven Relay Board: $75.50