Does this light have anything on it so that it can be hooked to my BCD - not my mask?
No there is no strap with this light
Yes. That mask adaptor comes off and It has a molded in slot that a one inch wide strap can go through. Also another slot that's 1/4 long, presumably for a laynard. Very bright light BTW, I also use it around the house all the time, batteries last a long time too.
You can try to attach male /female attachments that can be run through the piece wear the mask attachment runs and hook it to a D ring.
Unfortunately there is no distinct attachment point for any type of ring. There are however two narrow slots which the straps for the included strap go through to prevent loss which can be used to slide a piece of Velcro through and then you can simply put a ring on the Velcro. A split ring may also be passed through as well to eliminate the Velcro.
The mask strap device could clip the light onto a BCD, but the attachment mechanism would make it difficult to unclip and re-clip, especially with gloves. There is a slot on the body of the light - you can remove the mask-strap connector and thread a lanyard through the slot for hand-held use, or thread a zip-tie through to attach a stainless-steel or brass snap to clip onto a BCD. I use mine as a backup stowed in a pocket, it has a surprisingly bright white beam for it's size!
The UK Q40 with the mask attachment strap has a plastic molded loop just behind the light head (you can just see the edge of that loop on the far side of the website image between black rubber light head and the white mask attachment strap). The loop is intended for a hand lanyard. As such, it's a fairly small maybe a 1/8" x 3/8" opening. My Q40 is my backup light. I attach it to a d-ring inside a pocket with a mini retractor attached to that plastic loop, so one could certainly do something similar anywhere on a BC - with one caution. The mask attachment strap uses 2 more molded plastic loops. These side attachment points are not at any balance point, so the light hangs either diagonally bottom or nose first - not straight down as other lights which have a mounting point on the tail. As such, it's not very suitable for a DIR style mounting to a BC shoulder strap without some creativity (I've seen it done, making a knotted macrame-like sling down the light handle incorporating all the molded loops terminating with a new loop at the tail). The UK Q40 plastic loop is fairly robust for a molded plastic loop, I certainly wouldn't use it for a repel anchor but I've never broken a loop on the several units I own but I have lost them out of that pocket before I started using the mini retractor.
Yes. You can easily remove the mask strap and run a split ring or plastic tie thuough the slot in the light body that holds the mask strap in place. To that attach a clip or retractor that attaches to your BC. The light hangs vertically and stays out ouf the way nicely.
Yes...There is a flat opening to attach a brass ring to the side of the light. I have taken off the rubber attachment because I don't use it with my mask. I attached a retractable to the brass ring on one side and other end of the retractable is attached to the inside pocket of my BCD (there is a clip inside the pocket.) When I'm not using it, it fits nicely in the pocket and is securely attached. This is a great light...very bright light, lightweight and easy to use (even using gloves.)
Good Luck...Sandy C