Order a RXL Today & Get Massage Sandals Absolutely Free Your purchase includes one pair of Therapeutix Sandals with a Lifetime Warranty. These sandals are a “one size fits all” model and are designed to be operated when in a seated position. Operation of these sandals does require that you own a Therapeutix TENS Unit Electronic Massager or other compatible product. While not made to treat any conditions or diseases, these sandals have helped clients relieve tension, edema, foot pain, ankle pain, heel pain, restless leg syndrome (RLS), plantar fasciitis, and diabetic neuropathies.