This is a nice group of 3 calipers on one divider all made in Athol Mass.. From left to right they are as follows: 1) Marked Starrett, it's a 6" spring divider, No. 83, good condition with three small intials lightly etched on it. Nice shape, sharp points. 2) Marked Starrett, it's a 6" outside spring caliper, No.179, good condition with no owner's names on it, very clean! 3) Marked Athol Machine Company (Athol was purchased by Starrett about 1905), it's a 5" spring caliper, in very clean condition with no owner's marked. Made before 1906, a fairly rare machinist tool! 4) Marked Starrett, it's lock joint inside caliper No.38 with a fine adjustment knob on one side and a lock nut to hold the desired size. It's nearly like new condition, very clean, works perfectly! A nice clean group of measuring quality measuring tools!