Connecting Gas and Hydraulic Fluid Subsea has been done for a long time.
The first Standard used was the API 17D, this has a good track record but is replaced by the API 17H or ISO 13628-8. The ISO standard is now under revision, 13628-9 to also be included in 13628-8.
The first API 17D standard has a stab size of Ø35mm. The current ISO standard has two types: "A" and "B". Type A is made up of two dimensions: Ø35 and Ø43mm. Type B only Ø43mm.