Not really off-topic so please bear with me!
I've just bought an Osprey Hydration pack to fit my Talon 33. It comes with a 'powerful' magnet which attaches to the chest strap and allows the user to attach the drinking tube to said magnet, preventing the tube flapping in the breeze etc. The user pulls off the tube to drink and then re-attaches it. Easy. The usual warning re pacemakers (!) etc is prominently displayed on the packaging, and then it mentions possible interference with a compasses, phones, credit cards and 'electronic devices (?GPS). Hmm.
My compass usually lives in the rucksack top pocket ( unless I'm navigationally confused) - approx 8 inches away from the magnet, while my GPS will usually be either in the same location, or my hand - approx 8 to 12 inches away. My wallet, phone etc would also be buried in the rucksack. Would this be a safe distance away to prevent problems, or should I ditch the chest strap magnet?
Any advice gratefully received and apologies if this is in the wrong forum!
Bill