Conversation so far:
What is undertow?
their first full-length album.
How did this album do with the public?
The boost in popularity gained from these concerts helped Undertow to be certified gold by the RIAA in September 1993.
were there any hit songs?
Prison Sex.

Question: What are some significant fact that you can tell me about the album?
Self-contained rewrite: What are some significant facts that you can tell me about Tool's Undertow album?