Zenkoan singing bowls, often referred to in the context of Japanese Zen Buddhism as Rin Gong or Keisu, are metal bowls designed to produce a clear, sustained, and focused tone, serving as a sonic anchor for mindfulness and meditation. Unlike the complex, multi-harmonic Tibetan bowls, Zen bowls are typically smaller, thinner, and specialised for producing a pure, refined sound that marks specific moments in a ritual or meditation session. 
 
Meaning and Purpose:
Significance in Zen Practice: These bowls are used in Zen temples to mark the beginning and end of meditation, as well as to accompany chanting, focusing the mind on the present moment.
"Sound of Stillness": The act of playing the bowl is intended to bring a period of silence before or after the strike, helping to cultivate a "space" for meditation.
Symbolic Function: They represent the "universal tone" or the essence of emptiness (impermanence) in Buddhism, encouraging practitioners to detach from chaotic thoughts and return to awareness. 
 
Sound Characteristics:
Clear and Focused: Zen bowls produce a pure, resonant tone that is less "layered" than Himalayan bowls, making them ideal for creating a serene environment.
Sustained Resonance: They are known for a high-pitched yet sustained sound that gradually fades, symbolising the transient nature of existence.
Vibrational Impact: Despite their delicate tone, they produce a strong vibration that can be felt, helping to ground the practitioner and deepen relaxation. 
Striking: A striker is typically used to hit the bowl on the rim to produce a distinct "bong" sound, often used at the start/end of sessions.
Singing: The mallet can also be rubbed along the side of the bowl, causing it to "sing"—a technique used to create a long, sustained hum. 
 
These popular Zenkoan singing bowls are used in many temples all over Japan and China. They have a clear sound and a nice clean design.

Machine made singing bowl made of copper, zinc, tin and 8 precious metals
(Ag, Ni, Cd, Ru, Pd, Pt, Cr, Mn)
 
Production of Zenkoan singing bowls
These brass Zenkoan singing bowls are machine made with eight precious metals. At first, the metals are mixed and molten, then the material is rolled into sheets, and given its final shape in a moulding machine. Finally they get finished off and polished.
 
Size cm ± 10 - 11
Total weight 396 grams
Country of origin Nepal