Only the originals will do!The only choice for Ultimate Thermal Performance. Whether at work, rest or play our Heat Holders Thermal Long Sleeved Vests will keep you nice and toasty. Heat Holders thermal construction holds more warm air close to the skin, keeping you warmer for longer!They are rated at TOG 0.39. What does ‘TOG RATING’ mean? TOG is a recognised measure of a textile’s thermal ability. Simply put, the higher the TOG rating, the better a product is able to keep you warm.Copied by many. Equalled by none.(07/11)