I've never seen it either, so I looked at what they had on Amazon.
First of all, it is dirt cheap ($14).

If it's only $14.00 why is anyone even asking the question?
If $14.00 is an issue, then they shouldn't even be flying.
--

Tony Roberts
PP-ASEL
VFR OTT
Night
Almost Instrument
Cessna 172H C-GICE