The test tube provides a simple, sealed container to hold the tick after removal. This is practical if you want to save it for a short period to monitor it yourself or if you decide to send it for species identification or pathogen testing—some laboratories or veterinary clinics offer this service, especially in regions where tick-borne diseases like Lyme are prevalent. It's not a diagnostic tool itself, but a means of storage.
To use it, place the removed tick directly into the tube and close the lid. You can note the date and location of the bite on the tube with a marker. Keep it in a cool place if storing for more than a day. The tube is also compact enough to tuck into a first-aid kit, backpack, or pet supply bag, so it's available when you're outdoors in grassy areas, forests, or parks where ticks are common.