High-Class
High Grade, High Level
noun, な adjective, の adjective
A tall grade item is really just a high grade or high-class item.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
こんな高級なプレゼントもらえません。
I can't accept such a high-class gift.
これは中国で有名な高級茶なんですよ。
This is a famous high-end tea in China.
あの高級レストランはVIP専用で、入店には招待状か紹介状が必要なんだって。
That luxury restaurant is exclusive for VIPs, and to enter, you'll need an invitation or a referral.