盾牌 

Pinyin: dùn pái 
Meaning：Shield
Sentence：这盾牌保护他免受敌人的打击。The shield protected him from the blows of his enemy.

More: 

盾： 

Pinyin: dùn 
Meaning: Shield
Radical: 目
Stokes: 9
Traditional: 盾
Common words/Phrase:
盾徽 [dùn huī] 【coat of arms】
盾形 [dùn xíng] 【scutiform】
矛盾 [máo dùn] 【contradiction】
自相矛盾 [zì xiāng máo dùn] 【self-contradictory】

牌： 

Pinyin: pái
Meaning: Plate; signboard; tablet
Radical: 片
Stokes: 12
Traditional: 牌
Common words/Phrase: 
牌子 [pái zi] 【trademark; sign】
牌号 [pái hào] 【mark】
牌照 [pái zhào] 【license plate】
牌价 [pái jià] 【list price】
牌坊 [pái fāng] 【memorial arch】