Total length is 117 mm, battery tube diameter is 25,4 mm (one inch), battery tube length is 59,5 mm. The tube can be unscrewed from the diode assembly. The device comes with toggle button (protrudes slightly when the device is turned off) and a monostable button on a cable. You can easily switch between the two after unscrewing the rear cap of the battery compartment. External quality is very nice but I was disappointed that the adjustment knobs share a common leaf spring placed 135 degrees between them (visible on the last photo). This is not the best solution. Despite this drawback I can recommend this product.