Abstract: A biodegradable protective device adapted for a mobile device includes a main body and a protective portion. The main body is made of biodegradable plastic. The protective portion is made of biodegradable material, and the protective portion is connected to the main body and used to protect the mobile device from damage.

Abstract: The invention provides a vibration and noise absorbing mat structure which includes a flexible mat body including a sound-absorbing layer, a vibration damping layer and a buffer layer stacked in order. The sound-absorbing layer is made of a first foam body having a relatively low hardness. The vibration damping layer includes a sub-layer which is composed of a second foam body having a relatively high hardness, a third foam body having a relatively high elasticity and a fourth foam body having a relatively high hardness stacked in order. The buffer layer is composed of a fifth foam body and a plurality of buffer units spacedly disposed on a bottom side of the fifth foam body.