Translate the given Spanish text to English

[EX Q]: A wafer for placement in a pipe.
[EX A]: Una rodaja para colocarse en un tubo.

[EX Q]: The shell has at least one outlet opening (11).
[EX A]: La carcasa tiene al menos una abertura de salida (11).

[EX Q]: Disclosed are derivatives of icariin.
[EX A]:
Se describen derivados de icariina.