INTRALINE® MONO 29G 38 50 6-0 Threads are specially designed for accurate insertion and effective dermal retention providing optimum results. Monos are a single filament smooth PDO Thread filament folded in half.These are surgical threads made from Polydioxanone which is a colorless, crystalline, biodegradable synthetic polymer. They are designed to combat facial aging, skin stress, asymmetry and other related concerns.