There are several differences between the 2 products, Holts Radweld Plus and Holts SEALit. Firstly, they have been developed for slightly different markets, with Holts Radweld Plus aimed at retail customers who can use the product at home, whereas Holts SEALit is for the professional retail channel. However, the formulations are significantly different, with Holts SEALit being the latest development in Holts cooling system repair product portfolio. Holts SEALit has been developed to provide a permanent repair to the cooling system.