These are Grease Gun Hoses / High Pressure Grease Whip Hoses
What is it use for?
They connect to a grease gun to pump grease into machines.
You know machines that need greasing - like excavator bucket pins, truck propeller shaft, block moulding machines, bearings, tractors, generators, industrial machines.
The machine has small nipples called grease nipples / zerk fittings. This hose is what connects your grease gun to that nipple to inject grease.
1st picture (Black hoses):
• Standard high-pressure flexible extension hose with coupler head. Text on it says "WORKING PRESSURE 4500 PSI" - very high pressure.
• You screw it onto manual or pneumatic grease gun, the other end locks onto the grease nipple.