That's fine they are plastic. They won't scratch glass.
Hmm ok. I might try to find some rubber or a piece of acrylic to use as a sandwich plate and tighten them onto it.. I'm scared to scratch the new glass. First time I got rimless and starphire. I'm a baby. Dont want to tighten. But I know the mitras lx7 are heavier than the rest of the lights.
Glad I picked these. They are capable of being tall. If on the 11" setting they are like 15 inches tall!