Adam Rainer's Measuring Tape

Origin
Adam Rainer is the only person in recorded history to have been both a dwarf and a giant. He may have suffered from acromegaly, which causes gigantism from increased growth hormone output in the pituitary gland. He grew from 4 foot (122 cm) to 7 feet 4 inches (218 cm).

Effects
When wrapped around the waist it allows the user to shrink or grow in height from 4 feet to 7 feet, 2 inches. User will feel growing pains all at once.