Is this suitable for my bike?
So long as your crank spindle is 21mm or wider and is steel, then yes!
 

But is it safely secured?
Most certainly, there are 7 high powered neodymium magnets keeping the tool locked into your crank spindle.  The tool has been tested around the world through the Enduro World Series, with no reported failures.

How much does it weigh though?
Without bits, the tool itself is 80g.  With bits installed, it can come up to a 115g total.  Bear in mind that this weight, whilst minimal, is as low as it can go in your bike, which only aids in cornering prowess and overall bike handling.

Every tool you need to fix your bike on the trail, all sneakily hidden in plain sight!

100% designed and handcrafted in Italy, the All In Multitool features 6 customisable tool bit slots, plus storage for a quick link for your chain.  It is locked in place within the hollow of your crank arms with 7 high resistance neodymium magnets.  You'll never leave your multitool at home again.

The tool comes stock with a 3mm, 4mm, 5mm, and 6mm Allen key bits, a t25 torx head, and a #1 Phillips head screwdriver.  

If you find these bits aren't to your liking, then fear not!  Each piece is replaceable from your local hardware store, and you can fully customise which 6 tool bits you'd like to have.