The inner hole does not fit the inner filter! My inner filter was fine--all I wanted was the outer filter. However this filter is just the waffle filter without the tighter inner filter with a small diameter opening where nothing fits. There appears to be nothing that can fit inside the outer fixture as I just ordered the same brand inner filter and it still did not fit. This was a very expensive mistake and want to warn others to beware--the product shipped to me does not appear capable of inserting an inner filter. If this is what you want fine, but the Sundance Optima 880 spa is meant to have an outer and inner filter to optimize filtration
