"INCLUDES 2 ALUMINUM END CAPS, ONE CAP IS PERMANENTLY ATTACHED AND THE OTHER CAP CAN BE OPENED BY TURNING TWO WING SCREWS; BOTH END CAPS HAVE TWO BREATHER VENTS TO PERMIT CONDENSATION OR OTHER MOISTURE TO EVAPORATE OR DRAIN OUT; VENTS WILL NOT PERMIT INSECTS TO ENTER TUBE BUT WILL LET MOISTURE OUT; INSIDE LENGTH 11 FT., 4 IN."