These Sorby double ended calipers are indispensable in the turner's armoury for wall thickness and diameters: their design automatically transfers the measurement taken at one end to the opposite end, reading outside the work while gauging inside it. Two sizes, 4 and 7 in; the 7 in reaches into large vessels with narrow openings.

Specifications:

• Options: 4 in or 7 in
• Function: the measurement at one end transfers to the other; the 7 in has a deeper throat for restricted openings
• Made in: Sheffield, England by Robert Sorby