A pair of striking classic mid-century brown leather Tetrad Nucleus armchairs from the 1970s. They have a low deep seat with iconic scalloping on the seat and back.
Tetrad, who continue to make leather sofas and armchairs along with Pieff and Howard Keith were one of the leading British makers of armchairs and sofas in the middle of the last century.
These are 1st edition armchairs with removable arms. The range was built to be modular so armchairs could be joined to be used as 2/3 seat sofas. 
The price is for both armchairs.

Dimensions – Overall: Height 87cm x Width 82cm (70cm with arms removed) x Depth 100cm. Seat: Height 38cm x Width 50cm x Depth 55cm

Condition report:
In reasonable vintage condition. There is 3cm of missing stitching along one of the scalloped panels at the front of one seat (see the close-up image). 
The leather appears to have been recoloured several years ago.
The leather is in overall good condition. With just a few light surface scratches to the leather. There is a 2cm cut to the side of one of the chairs that does not penetrate the leather (see the photo). 
Both chairs sit firm, no wobbles, no repairs to the polished frame.
The leather is nicely aged with pleasing creasing. We have nourished the leather.