Complete O-ring kits that make servicing easy Horizon is now utilizing the AS568A O-Ring standard used by the O-Ring industry in order to bring a standardized approach to the pool and spa industry. The current active Horizon part number for an o-ring is 90-423-5xxx, where xxx represents the AS568A designation. This designation ranges from -001 thru -932, in order of smallest to largest first by cross section then by diameter. Please see substitute item number under “Quick info” for the current SKU for this item.
Exploded parts diagram: This part is shown on the Cartridge Filter, Pentair PacFab, Mytilus B exploded parts diagram.
🔧 Cartridge Filter, Pentair PacFab, Mytilus B – exploded parts diagram

The numbered parts below make up this assembly. Parts we stock are linked – click any to view.
| No. | Part |
|---|---|
| – | Ro-Kit 264, Pac-Fab Mytilus B Filter ◀ this part |
| 25 | O-Ring, 1-3/4" ID, 1/8" Cross Section, Generic |
| 24 | Retaining Ring, Pentair PacFab ST |
| 23 | 16-110-W013K23 |
| 22 | 16-110-W013K22 |
| 21 | O-Ring, PentairPacFab Mytilus/Star, 12" Tank Body, O-99P |
| 20 | Bolt, Pentair PacFab, Pump/Filter, 5/16-18 x 4-1/4" |
| 19 | Washer, Pentair PacFab, Pump/Filter, 5/16" |
| 18 | Clamp Knob, Pentair PacFab, Pump/Filter, 5/16-18 |
| 16 | Clamp Ring, Pentair PacFab Mytilus/ST |
| 15 | Tank Base, Pentair PacFab Mytilus/ST |
| 14 | Outlet Pipe, Pentair PacFab Mytilus B |
| 13 | O-Ring, 3-1/2" ID, 3/16" Cross Section, Generic |
| 12 | 16-110-W013K12 |
| 11 | 16-110-W013K11 |
| 10 | Cartridge Adapter, Pentair PacFab Mytilus/Mitra, 2 required |
| 9 | 16-110-W013K9 |
| 8 | Strainer Assembly, Pentair PacFab Mytilus/Mitra |
| 7 | 16-110-W013K7 |
| 6 | Nut, Pentair PacFab, 3/8-16 |
| 5 | Washer, Pentair PacFab, 3/8" |
| 4 | O-Ring, 7/16" ID, 3/32" Cross Section, Generic |
| 3 | 16-110-W013K3 |
| 2 | 16-110-W013K2 |
| 1 | 16-110-W013K1 |










