1/8th wave GNSS monopole antenna

[uer166]

I'm looking for a compact antenna for 1575MHz, and stumbled upon this little antenna that looked like a half-wave monopole:

https://www.digikey.com/en/products/detail/taoglas-limited/TS.07.0113/5120278

Upon taking it apart, 80% of the height is just the orange plastic with no metal. This is quite dumb for my handheld application where I want to minimize size. Can y'all confirm this is a 1/8th monopole based on measurements? The element is approximately 25mm long.

What is the compromise with such an antenna? And finally if someone knows of another part that's similar but without the extra plastic that would be ideal.