50A Starrett Trammel Heads (Adjustable) includes 2 Heads 2 Points Pencil Socket

50A
Starrett Improved Trammel Heads with divider points, pencil
socket

Used to measure the distance between points that are too great to be
reached with dividers. The heads are die cast with black wrinkle finish
and have hardened, forged steel divider points. The points screw into
the heads, and the pencil socket accompanying each set of trammel
heads can be used in place of either point. 50A has an adjustable point.
Longer points (5"/125mm) are also available. A beam is not furnished
with these trammels. The heads will accommodate a beam up to 3/8"
(9.5mm) thick and 3/4" (19mm) wide.