Equipment / Piece / item of equipment
UsageEquipment is normally uncountable. Use a piece or item of equipment for one device and pieces or items for several.
Equipment
Use when
You mean the tools, machines or devices needed for a purpose collectively.
Example
“The team needs new video-conferencing equipment.”
Piece / item of equipment
Use when
You need to count an individual device or tool.
Example
“Each item of equipment must carry an asset tag.”
Quick check
an equipment, three equipments, new equipments
Usage note