It's not a part of the saddle- that looks like some sort of home made bag holder or something. I can't imagine any big company (with any sort of legal department) advocating drilling into a seatpost.
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*Recipient of the 2006 Time Magazine "Person Of The Year" Award*
Commence to jigglin’ huh?!?!
"But hey, always love to hear from opinionated amateurs." -says some guy to Mr. Marshall.