This Colt manufactured first variation main (firing pin) spring measures approximately 2" in length and is for the earlier model 1908 Hammerless Vest Pocket semi-auto pistol in 25 ACP caliber and is in very good condition with light wear. (file photo)

Note: Colt model 1908 Hammerless Vest Pocket pistols with the following serial numbers have been observed with this part: 5933, 58366, 91759, 98889, 121759, 135203 & 222749