Lufkin® Red End® Extension Rulers
For carpenters and other professional craftsmenGraduated slide rule extends up to 6 inHX46 has hook zero falls at inside of hook, for distance measuringSlide rule runs under friction in T-lot and stops at each end to prevent sliding from falling outX46F has flat, inside markings: numbering begins on inside of ruleX46X has two 6" extension slides: an extension is ready for use on the first section