Filled container (like ref. 726) with urine or another bodyfluid needs special requirements when transported by Letterpost. Use proper and solid outerpackaging like the MiniMailBox (ref. 20121). The container should be packed in an absorbent pouch and after that put in a leakproof SafetyBag with bubbles for extra protection. Another possibility is to use a transportblister like the ref. 460712, which can hold 2 containers and when the container is rolled in an absorbent sheet , placed in the transportblister and finally in the SafetyBag.