Maytronics Dolphin Supreme M4/M5 ultra-fine filter cartridge kit (4-pack, 50 microns) - 9991432-ASSY

Maytronics Dolphin Supreme M4/M5 ultra-fine filter cartridge kit (4-pack, 50 microns)

This is the genuine Maytronics kit of four replacement ultra-fine filter cartridges rated at 50 microns for the Dolphin Supreme M4, M5, Explorer, and Zenit series robotic pool cleaners. Each accordion-style cartridge slots into the robot’s lateral filter bays and intercepts fine particulate — sand, silt, dust, iron particles, and limestone residue — that coarser media passes straight through.

What these filter cartridges do in the Dolphin

The 50-micron filtration threshold means the cartridges capture sub-millimetre debris that standard or fine-grade filters miss entirely. Water drawn through the robot’s impeller passes across the pleated accordion surface; the expanded face area maintains flow rate while trapping fine particulate in the folds. When the cartridges load up, suction drops and cleaning run-times extend — the clearest sign a swap is overdue.

Which Dolphin models they fit

These cartridges are confirmed for the Dolphin Supreme M4, Supreme M5, Liberty, Explorer, Explorer Plus, Bio Suction, Pulit, Zenit series (20/30), Active, F Series, and SF Series. The frame dimensions and S-clip retention system are shared across this platform, so a single kit covers all of them. Do not fit these to Nautilus, Nautilus Plus, or Nautilus CC Plus — those models use a different cartridge geometry.

Signs they need replacing

Reduced suction or a noticeably shorter effective cleaning cycle is the first indicator. Visually, a cartridge that no longer rinses clean under a hose — with debris embedded deep in the pleats — has reached end of life. Filters used in pools with fine sand or high algae loads typically need replacement every 6 to 12 months; pools with lower debris loads may extend that interval slightly.

How to install them

Open the filter covers on both sides of the robot and release the S-clips to remove the spent cartridges. Align the locating tabs at the base of each new cartridge with the grooves on the base frame, seat the cartridge flush, and close the S-clip until it clicks. Do not force the cartridge — if resistance is felt, recheck tab alignment. The full swap takes under five minutes with no tools required.