Talk of a Porsche 911 hybrid dates back several years, but we’re now just weeks out from the debut of an electrified version of the sports car icon.

Prototypes for various 911 hybrid grades have been spotted testing over the past 12 months and Porsche on Monday released photos of some of the testing and said development is complete.

The automaker also confirmed the debut for at least one 911 hybrid grade, likely part of the 911 Carrera family, on May 28. The photos show prototypes for what appears to be a 911 Carrera or Carrera S, both in standard form and with an available Aerokit package that includes a fixed wing.

The 911 Turbo is also likely to be electrified at some point, judging by previously spied prototypes.

Porsche didn’t reveal any details on the hybrid system but said it has been developed with a focus on performance. Racing driver Jörg Bergmeister managed to lap Germany’s Nürburgring in a time of 7:16.934 with one of the 911 hybrid prototypes, which Porsche said was 8.7 seconds quicker than the time for corresponding grade in the current 911 family.

Porsche CEO Oliver Blume has previously said the 911 hybrid will be more along the lines of the former 919 Hybrid LMP1 race car, and not a plug-in hybrid like the 918 Spyder hypercar, as well as Porsche’s existing hybrids. This means the hybrid system will likely only be used to support the gas engine and recover energy under braking, and not provide any substantial electric range (if any), thus avoiding the need for a big and heavy battery.

The 911 hybrid’s introduction will coincide with a mid-cycle refresh for the current 992-generation 911. Earlier prototypes reveal that the updated 911 will also receive some styling changes, plus a fully digital gauge cluster similar to what Porsche has already introduced in its other models.

The first members of the updated 911 range are expected to reach the U.S. as 2025 models.