These koi pond window top grade 316 stainless steel frames are viewing fish friendly pond feature accessory, easy to fit and come with a koi window lifetime guarantee. They simply get built in with the block work, couldn't be easier to put a window in your pond. They are designed to fit a 220 mm thick wall, the lugs on the ends go between the courses of block/brick work to hold the koi pond window frame in position, with a lintel/copping over to finish. This design brings the glass to the front of the wall so that the glass window pond feature accessory, the stainless surround and the render or brickwork are finished neatly on the front face. This is also an advantage to get closer to your koi/ fish for a regular health inspection. The frames come with three tubes of silicone and the plastic packers to level the glass pond feature . The bottom of this pond window viewing frame and the recommended glass can safely be fitted to 750 mm from the surface. For greater depths, infinity style pond frames, lengths of frame or thickness of wall, please ask about our other bespoke pond window products. Or if you need a different size just contact us on 01255814101 to discuss your requirements for koi pond viewing window stainless steel pond feature and accessory.