If you control a Synchro Monster, you can Special Summon this card (from your hand). You can only Special Summon "Junk Dragonlet" once per turn this way. When a Synchro Monster you control declares an attack: You can banish this card from your GY; that monster you control gains 800 ATK until the end of this turn. You can only use this effect of "Junk Dragonlet" once per turn.