Tree trunk protectors a great addition to your recovery kit.  They are designed to protect the tree used as an anchor point for your recovery. If you use anything other than a tree trunk protector you risk damaging both the tree and your winching line and over time may also cause the tree to die.  

WARNING: Cancer and Reproductive Harm -  www.P65Warnings.ca.gov .  PRODUCT WARNING/LIABILITY DISCLAIMER:  Aftermarket accessories are intended to modify and/or prepare a vehicle for uses which exceed conditions anticipated by the vehicle manufacturer. These uses include high performance demands and negotiation of rough terrain. These conditions have extreme variance and cannot be controlled by the vehicle manufacturer or aftermarket accessory manufacturer. Therefore, the safe control of your vehicle is entirely your responsibility. Do not purchase parts unless you are willing to accept this responsibility. Do not install any part that you do not feel competent at installing without causing present or future injury to yourself or others; consult a professional installer.  Modification of your vehicle to enhance performance can result is dangerous situations that may result in bodily harm. The buyer hereby assumes all risks associated with any such modifications. The seller will not accept responsibility for personal injury or property damage arising from the failure of any parts.