The CoolSprings MINI-LE is a compact passive stereo spring reverb from Zerotronics. It's a MINI because it's small (2"H x 6"W x 9"D, 3.7 lbs) and an LE because it's a Limited Edition.
Small enough and light enough that you can take it with you to a mixing session, just as you take your favorite microphones to a tracking session. Or take it on the road and use it for live PA.
Inside the box is a pair of rare NOS (new old stock) dual-spring reverb mechanisms, manufactured by Baldwin in the late 60's for use in electronic organs. A unique tapered spring design creates a delay line in which the delay time is inversely proportional to frequency. The result is a smooth reverb with a remarkable degree of diffusion.
When you hear it, you won't believe your eyes. When you see it, you won't believe your ears.
The CoolSprings MINI-LE is a limited edition, $795 USD.