This card cannot be used as a Synchro Material Monster, except for the Synchro Summon of a "Scrap" monster and all the other Synchro Material Monsters must also be "Scrap" monsters. When this card is Normal Summoned, you can select 1 "Scrap" Tuner monster in your Graveyard and Special Summon it.
Instead of using the monster you special summon as Synchro material, a quicker way to make use of it is to destroy it with other Scrap cards' effects to gain quick advantage. Scrap Orthros is another Scrap Tuner that you can special summon by destroying a Scrap monster you control, you can then recover a Scrap monster from your graveyard with his effect.
Scrap is an archetype of monsters that like to destroy themselves to gain advantage with their effects. These support cards help you destroy them and also give you additional benefits when a Scrap monsters is destroyed. You can use Scrap Lube to revive Scrap Shark or Scrap Kong with their negative effects negated.