In 1984, SPIROTECHNIQUE revived the diaphragm regulator: the famous PRO series.
This regulator will first come out with a neoprene valve, then in 1984 by a much less fragile Teflon valve. It will be available in no less than 6 versions !!!! (PRO, PRO S, PRO R, PRO RS, PRO RT (Teflon valve in 1985) then PRO R with plastic cover (1985) then to finish PRO XL in 1986. Each version being mountable with a French, international seat or a DIN mounting, a real Chinese puzzle!
In this photo the simple version of the PRO regulator, it is new and has the serial number 1559, it probably dates from 1983.
Here is the PRO S version, the difference with the previous model and that the humid room on the first floor is insulated with an oil bath, it probably dates from 1984 and has the serial number 217.
I present to you the SPIRO PRO R serial number 1956, it dates from 1984. It is characterized by the PRO by its second stage equipped with a sensitivity adjustment wheel.
Here is the SPIRO PRO RS serial number 1793, it dates from 1984. It is characterized by the PRO R by the addition of an oil bath insulating the humid chamber of the first floor, making it resistant to the phenomenon of icing in cold water, it is the ancestor of SPIRO ARTIC.
I present you the SPIRO PRO RT serial number 2972, it dates from 1985. The letter "R" s means as usual that the second stage is equipped with a sensitivity adjustment wheel, on the other hand the letter "T "is there to mean that the first stage is fitted with a teflon valve because the neoprene valve of the first series of 1984 presented a defect in premature wear.
Here is the last version with second metal stage of the SPIRO PRO R version, it dates from 1986. It has the cover and the push button type XL plastic case like the version of the AQUALUNG R.
Here is the SPIRO PRO XL with rounded mustaches , this version dates from 1984.
Here is the SPIRO PRO XL with US DIVERS mustaches, this version dates from 1985.