Waterproof Silicone Neck Seal have no chemical or environmental sensitivity and they have 40% better stretch than latex seals. 100 % UV and Ozone resistant. Extremely stretchable. No latex allergy. No maintenance. Easy donning and doffing. Extremely fast mounting. Bellow design for easy movement. Interior Glide Coating The inside of the seal is treated with a glide coating for easy donning. Safety Ridge- The safety ridge ensures that the seal stays in place. Fits SI-TECH Neck Tite System.