Minecraft wiki entry for Hopper, associated text: 1 Obtaining
1.1 Breaking
1.2 Entity loot
1.3 Crafting
2 Usage
2.1 Container
2.2 Crafting ingredient
2.3 Redstone component
2.3.1 Redstone signals
2.3.2 Collecting items
2.3.3 Pushing and pulling items
2.3.4 Container interactions
3 Sounds
4 Data values
4.1 ID
4.2 Block states
4.3 Block data
5 Achievements
6 Video
7 History
8 Gallery
9 Issues
10 Trivia
11 References