NEW PRODUCT - SPECIAL HALF PRICE DEAL!! Only £35.00. Limited time offer. The Obi TENS Plus is the best of both worlds. ‘Super simple’ meets ‘Fully functional’. This dual channel maternity TENS machine is also a contraction timer, recording your last 5 in-between contraction times. The Obi TENS Plus can also be used for post labour pain, such as shoulder, back, period pain and much more.