I found Aquapet's customer service excellent, and happily rate it five out of five. The cage extension was quite difficult to fit, particularly when it came to releasing the original two white clips 'locking' the roof on. It is less secure now as the clips are loose, and a pair of translucent ones in the package do not seem to fit anywhere! However, it has not capsized so far, held by the bottom white section when lifting to clean. The two budgies needed more space when 'indoors', and are very happy with the height of their top perch in their new tower block.