www.MajorSurplusNSurvival.com sells 6 heavy aluminum instrument tins @6 for $10.00 They're in the products section under military surplus,ammo boxes.Altoids tins are readily available. There was a concern over the mints themselves,as the calcium base was derived from cattle bone.Some British Physicians expressed concern as 'Mad Cow' is a persistant critter!<br><br>