Bag of Binding Bands

This bag of rubber bands contains 2d12+5 rubber bands. The rubber bands can stretch to a width of up to 5 feet in diameter. When these rubber bands stretch around any amount of objects or creatures, and the command word "Seal" is spoken, the rubber band(s) lose the ability to stretch and become unbreakable without the use of slashing damage with a magic item or spell. When binding a creature, the creature can attempt to slip out of the rubber band with a dexterity saving throw (dc 13 + 2*x, x being equal to the number of bands used to bind the target). The creature gains advantage on this throw if the band(s) are placed in an area where they can easily be slipped off, and disadvantage if placed in an area where removal would be very difficult. Once a rubber band has been removed or broken, it loses its magical properties and becomes a regular elastic band.