The tough credentials of the StoreJet 25M3 are immediately apparent thanks to its dimensions and mostly rubber finish. While the drive inside is 100 x 70 x 7mm, the external dimensions are 129.5 x 82.4 x 20.4mm. This is a little larger than some portable hard drives but is still quite impressively petite considering the protection on offer.
Keeping those bumps at bay is a triple layer of protection with a silicone inner holding the drive, a hard plastic shell surrounding this then a rubber coating finishing things off. Oddly the rubber coating doesn’t cover the end where the ports and button are, seemingly making them a little more vulnerable. However the test specification does note that the subject must pass drops on all edges so this clearly isn't a weakness at least when it comes to passing that test.