Viridian sells an instant on laser. You can get it in red or green and it comes with a holster. It's activated by a small magnet installed in the holster. The activation button has the modes, off, constant laser and strobe. I have one on my Sig P938 and it works great. Don't think I'll put one in my Hellcat at this time. I've got an Alien Gear holster for both weapons and they make holsters for the instant on lasers.I have the standard hellcat and was interested in maybe getting a laser for it but wasn’t sure what would be a good one that had an instant on feature and getting a different holster also. Would like some recommendations .