Thera-band xtrainer gel hand exerciser, set of 4 (red, green, blue and black) the thera-band hand xtrainer is truly a cross functional device – with applications ranging from rehab to stretching and strength training. It supports a variety of finger, hand, wrist, and forearm exercises, making it an ideal replacement to putty and an economical alternative to hand extensors. Thera-band hand xtrainer is an innovative product that offers several key benefits: patented formula supports hot / cold therapy, ease of use and optimal form. Economical and intuitive; ideal for home exercise progressive for clear measure of progress. Supports broader range of exercises. Clean and professional. Available in 4 levels of resistance. 4 piece set – 1 each: red, green, blue & black.