#BLH2 Rigid Tube Mount. 19mm-42mm Diameter for BLBP2 Profoto B2 Cage. The Tube Mount locks into a 1/4-20 threaded adapter and features 2 anti-rotation set screws. The #BLH2 can mount almost anything with a female 1/4-20 adapter to a tube or rail. The #BLH2 is machined out of high strength aluminum manufactured in our PMG Machine Shop. Made in the USA.