Case compatibility: If you are building the Hydronium Eurorack DIY kit, before you begin, check to be sure the Main PCB fits between your case’s rails. The original Hydronium Main PCB (Revision C2) fits in all cases with Vector rails, but some other styles of rails (Doepfer,etc) have less clearance between the rails, and this module may be too tall for it. If the Hydronium PCB doesn’t fit, you may exchange it for a revised Main PCB (Revision C3) that is 2mm narrower between the rails.