Polaris Zodiac 3900 Chain Tensioner (39-120) hydrodynamic and this 4

and this 4

Useful for repair and visible fitting refresh work

Designed for dependable surface-debris removal

When a very large heavy-profile O-ring becomes worn

The Hayward SP14341PAKA body with bulkhead is designed for compatible inlet and outlet applications and features a 1 inch by 1 inch configuration

Polaris Zodiac 3900 Chain Tensioner (39-120) hydrodynamic and this 4Polaris Zodiac Chain Tensioner [3900] is a replacement part for compatible Polaris and Zodiac pool cleaner systems. This component helps keep the drive chain properly positioned so the cleaner can maintain steady movement during normal operation. When small cleaner parts wear out, even minor fit or movement issues can reduce cleaning coverage, create leaks, or cause the cleaner to move less reliably. Use part number 39 120 to help match this item to