Standard Filter for Blue Whale spa – Fits Many Hot Tub Models

Amazon.co.uk Price: £25.95 (as of 23/10/2021 19:39 PST- Details)

This filter fits many hot tubs and spas, see list below.
Outside Diameter 4 15/16″ (12.5cm)
Hole Diameter 2 1/8″ (5.4cm)