To accompany my collection of regulators I began to collect some accessories from La Spirotechnique, including masks, fins, lamps, knives and more particularly analog instruments such as depth gauges.

I was particularly attracted by these and to my greatest surprise these exist in several variants at the level of the dials for example.

I therefore amused myself by establishing a small classification, taking inspiration from that of philately which was one of my childhood passions.

There are surely other variants that I have not yet discovered and it is with pleasure that I will exchange your information in order to establish a typology as precise as possible and why not a chronology.