prayer wheel

This term refers to a specific ritual object used primarily in Tibetan Buddhism. It is viewed not as a tool for requesting favors, but as a mechanism for generating spiritual merit and purifying karma through the physical act of rotation.

Because it is a compound noun referring to a physical object, it follows standard English countability rules. It is typically used in a concrete sense, describing either a handheld device or a large, stationary wheel found in monasteries.