Merlin Industries CGLASSES Glasses for COOL! Holographic Pool Liners - These glasses are for use with COOL! Holographic Pool Liners. COOL! pool liners feature styles that seem regular upon first glance. However, once the compatible COOL! glasses or goggles are worn, the liners showcase a mesmerizing holographic effect. The glasses can be worn for those who want to enjoy the effect on land, while goggles can be worn for those who prefer the under water experience. Please note that goggles and holographic liners are sold separately.