Product Dimensions: This underground aquarium cave size is 13 × 13 × 7 cm, great for aquarium decorations, model making, terrariums, miniature gardens, and marine aquariums. Product Material: This fish tank hideout tunnel is made of non-toxic, harmless resin; it is durable, natural, safe, and eco-friendly. This tunnel is tough enough to resist daily wear in tanks. Creative Tunnel Design: The pleco cave adopts a corner tunnel structure and can be placed in every corner of the fish tank; this maximizes your layout options without taking up central swimming space. Stable and Safe: This fish hideout for aquarium featuring smooth edges and a stable structure. The stable base stays firmly in place even when pets dart in/out or bump it, preventing tipping. Versatile Application: Each fish tank cave is individually sculpted and hand-painted to mimic the intricate textures of real driftwood, ideal for aquariums, fish tanks, and shrimp tanks.