Product description C4 Sideral Apnea Pants (3 mm, 5mm) SIDERAL TWO PIECES. Two pieces wetsuit with the same exclusive design featured by C4 spearfishing wetsuits. The inner lining is extremely elastic and the wetsuit is glued and sewn on the inside. Sideral two pieces are available in 3mm and 5mm neoprene, featuring five sizes. Wetsuits specifically designed for freediving made with glide skin neoprene on the outside and elastic single lined neoprene lining on the inside. The neoprene rubber is certified for the absence of any chemical materials which can damage the environment or human health such as phthalates and latex. It also features great resistance to compression and an excellent elastic return.