first4magnets™ FB160450-5 16 x 4 x 50 mm Long Ferrite Bar Magnet with North South & Identified (Pack of 5), Metal, Silver, 25 x 10 x 3 cm, 5 Units : Amazon.de: Home & Kitchen
First4magnets Digitalen Pole-ID - zeigt sofort Norden & Südpol (1 Packung), Silver, 25 x 10 x 3 cm - Amazon.de
Geodetic Challenges on Precise Positioning & Navigation using GNSS Raw Data on Smartphones along the NAVKA-Disy RaD Project