The original KLM end caps were at most 1/16 in thick. The replacement ones
are thick enough to stop intrusion by any flying things, including plastic
owls heading to true north.
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
TowerTalk mailing list