20% Discount Code at Slendertone - Limited Time Only Written by Optimus Performance Marketing on December 13, 2011. Posted in Awin, Health & Beauty, Offers/Promotions, Voucher Codes Save 20% this week at Slendertone with our Voucher Code. The offer is valid on any basket size and any product, but hurry this offer must end Friday 16th December 2011. Code - SLTXMAS20 Promotion - 20% off any basket value Expires - 16-12-2011