The original and famous "mineral tack". While it resembles ordinary "sticky tack" used for hanging posters, this is a special easy to remove formulation that is chemically inert, non-hardening, non-greasy, non-staining, and leaves absolutely no residue on your mineral specimens or precious treasures. There is a reason museum curators and mineral collectors the world over use this specific putty to secure their specimens to their displays. Definitely not just for rocks, either! This stuff is great for anything that needs help standing upright, to be stuck to something else, or hung from the wall, or simply needs extra staying power to withstand: bumps, vibrations, curious (or spiteful) cats, earthquakes, wagging puppy tails, clumsy toddlers, and other misfortunes! Infinitely reusable with no mess, no residue, no holes, no messy tapes, no glues. Sold in approximately 1.8 oz (50g) packages. Each package contains six 3.5" (9 cm) strips that are approximately 3/8" (8mm) in diameter. There may be a slight variance in weight (+/- 0.1 oz) and length (+/- 1/4") but we do our best to err towards too big rather than too small. Enough to mount about 6-12 cabinet (fist-sized) mineral specimens, 1-3 dozen miniature (golf ball sized) specimens, or up to hundreds of thumbnails. This will naturally vary depending on how your specimens "sit", their shape, weight, etc. and you may get more or less mileage out of a pack. It doesn't expire so stock up for when you need it and save by buying multiples. Works great on our customized display stands too. See our eBay store page for all our stand options!