Siemens-Spiegel-Hypomediar 20cm f6.8  type_Lens & Sensor Cleaning This developer is designed for

This developer is designed for use on photographic paper only

diaphragm moves well

daylight-safe 4x5 developing tank that can process up to 4 sheets at a time with only 475ml of solution

You can change the battery without taking off the case

but looks pretty cool

Siemens-Spiegel-Hypomediar 20cm f6.8 &nbsptype_Lens & Sensor Cleaning This developer is designed forSiemens Spiegel Hypomediar 20cm f6. 8 lens for C mount. This is a unique mirror lens design with an adjustable diaphragm from f6. 8 f16. Designed for 16mm c mount cameras, this lens will not cover Micro Four Thirds (see pic for coverage at infinity), but will cover Super 16 image area. A rare lens in good condition, with some cosmetic barrel wear, oil on diaphragm blades, good optics.