Hayward 2" Slip In Line Sight Glass (SP1074S) aquastar An auxiliary topside panel can An auxiliary topside panel can make a spa feel much more complete because it gives users access to important functions from a second location instead of forcing every adjustment through the main control point this part is well suited for a matched replacement approach that restores balance throughout the assembly rather than leaving mixed wear levels in place The Hayward in line sight glass is designed for compatible plumbing and filtration applications where visual line inspection is needed supporting easier troubleshooting and service checks