Vylon Prism

Level 4 LIGHT/Thunder Tuner Effect
1500 ATK / 1500 DEF

If this card is sent from the Monster Card Zone to the Graveyard: You can pay 500 Life Points, then target 1 face-up monster you control; equip this card to that target. If the equipped monster attacks or is attacked: It gains 1000 ATK during the Damage Step only.

Rulings – Yugipedia

Printings:

Duel Terminal 6a: DT06-EN022 (Duel Terminal Rare Parallel Rare) - 2012-02-03
Hidden Arsenal 6: Omega Xyz: HA06-EN007 (Super Rare) - 2012-07-24
Battle Pack 2: War of the Giants: BP02-EN108 (Common) - 2013-06-28
Battle Pack 2: War of the Giants: BP02-EN108 (Mosaic Rare) - 2013-06-28
Realm of Light Structure Deck: SDLI-EN019 (Common) - 2014-06-27

Prices:

Cardmarket: 0.09 €
TCGplayer: $ 0.13