I purchased this attachment in order to help with my recovery from Total Knee Replacement surgery, since cold therapy was recommended by the Doctor for post surgical swelling and tightness. While a cold therapy machine was useful while at home and in bed, it was not practical while on the go and wasn’t portable. This TheraGun cold attachment solved that problem and gave the convenience of a compact cold source that did not require water or ice or any bulky equipment. Just attach it to the Theragun, select your level of coldness, and go. This has been a huge help in my recovery, I keep the entire setup with me, I use it in the car, at my desk in my office, in the gym doing rehab, and after Physical Therapy. It is the most useful and portable tool in my recovery kit, and has made a world of difference.