Trans. Orange Slope 1 x 1 x 2/3
These tiny little slopes, often called cheese slopes by us LEGO fans, are great for making patterns when turned on their side.
The transparent ones can be used as headlights for cars.
The trans orange ones can be used as lava.
Other references for this part: 54200, 35338, 50746, 4244369, 6245265, 158788-105