Billabong 4mm Furnace Synergy Ladies Wetsuit 2020 - Mermaid The Billabong Furnace Synergy offers premium performance at an economical price. Constructed with triple glued and blindstitched sealed seam and Superflex internal neoprene tape to help prevent the seams from taking in water and improve the longevity of the suit. Large Furnace thermal lining on the front and back help to keep you warm on those colder days and this thermal lining also has quikdry features so that you don\'t need to climb into a wet wetsuit the following day! This model features a chest entry system and strategic seam placement to offer ultimate flex and freedom of movement when out on the water. The 4/3mm thickness is ideal for Spring, Summer and Autumn use in the UK and Europe.