Thomson Elite 275 is as you have guessed is a 650B wheelsed frame. The frame is made by Lyndsky in the USA. It is of course Titanium. due to the large diameter tubes the frame weight is around 2kg.
The frame however is a work of art. It requires a Q/R hub rear (135mm spacing). The headseat cups are pressed in.
The frame comes with a Thomspon seat post collar, cane creek headset, Thomson X4 70mm 0 degree stem, Thomson MTB riser titanium 780mm bar and Thomson Elite Covert internal dropper post (31.6mmx125mm).
Limtied lifetime warranty applies.
The SRP is £3250 but the frame and all this kit is now £1200.
Two sizes 19" and 21". The geometry is american so is in inches. To convert to mm multiply by 25.4.