Pull the lever and only one will extend outward for you to clean, re lube and push back with another tool of yours. Repeat for each piston by rotating and or flipping the tool to be able to use it on all pistons.
eBay
NUTT 4-Piston Hydraulic Cutoff Brake E-Bike & Electric Scooter Disc Brake for Zero 10X/11X, Vsett 10+/9+, Kaabo Wolf Warrior 11
Aliexpress UK
A necessary Tool For Removal And Installation Of New Brake Pads. It is quick and easy to use disc brake spreader,when Separate Pistons In Their Calipers Using it. Professional and Heavy Duty. Applied to most kind of cars.
eBay
Shimano XT BR M7120 BR-M7120 MTB Disc Brake Caliper 4 piston with brake pads resin or metal DO2S/D03S/N03A/N04C original
Aliexpress UK
【Multifunction Tool】The pneumatic brake caliper can be used to press the brake piston of various models, press back the brake piston, adjust the brake pump, replace the brake pads, etc. For air pressure assisted resetting of brake pistons.
eBay
HEPPE Bicycle Caliper Piston Resetting Tool Bike Caliper Piston Press Tool for 2-Piston 4-Piston SHIMANO/SRAM Brake Caliper
Aliexpress UK
A quality disc brake piston wind back tool by Alpha. Retracts parking brake piston prior to installation or removal of pads. Use with 3/8"Sq drive ratchet wrench and extension bar. Universal Alpha Disc Brake Piston Remover.
eBay
Disc Brake Gap Regulator Bike Brake Pads &Rotor Alignment Tool Disc Brake Alignment Tool Bike Brake Pads Prevent Brake-rotor Rub
Aliexpress UK
This tool kit allows you to rewind the pistons in brake calipers by hand without damaging the gaskets in the pistons. Save money on garage fees and safely rewind your brake pistons using this kit!
eBay
Bicycle Hydraulic Disc Brake 2 Piston MTB Brake Caliper IIIPRO E2 Mountain Bike Brake Oil Pressure 800/1550mm Front Rear Brake
Aliexpress UK
This is a cube tool to rotate piston back into brake calipers when replacing brake pads on vehicle with rear wheel disc brakes, and it is used with 3/8" drive ratchet and extension. In addition, made from steel, the disc brake piston tool is very sturdy and durable, and you can use it on many universal vehicles with 4 wheels.
eBay
IIIPRO E4 Mtb Brakes 4 Piston Hydraulic Disc Brake 800/1550mm Ultra Light MTB Brake Cooling Oil Pressure Bike Disc Brake
Aliexpress UK
In addition, made from steel, the disc brake piston tool is very sturdy and durable, and you can use it on many universal vehicles with 4 wheels. This cube tool rotates piston back into brake calipers when replacing brake pads on vehicle with rear wheel disc brakes.
eBay
SPEEDONE 4 Piston Hydraulic Brakes MTB Disc Brake Front Rear Brake 850mm/1600mm XC AM HD E-Bike Disc Brake BOLANY With Cooling
Aliexpress UK
This tool kit allows you to rewind the pistons in brake calipers by hand without damaging the gaskets in the pistons. Save money on garage fees and safely rewind your brake pistons using this kit! Spindles threaded for right and left handed users.
eBay
HEPPE Bike Hydraulic Brake Caliper Ceramic Piston MTB Road Bike Disc Brake Piston For M640 M810 M820 M7120 M8120 M9120 4-Piston
Aliexpress UK