If you only have one gear, sometimes you need to change gears to make sure that you have a high or low enough gear to drive. Using a chain whip/sprocket puller for 1/8" sprockets (SR-18. 2) from Park Tool you will no longer have to settle for using a 3/32" sliding chain whip when installing or removing 1/8" sprockets which often results in bleeding knuckles. On the opposite side there is a 1" socket wrench if your single speed bike has a free hub and the key is heat treated for increased strength and the molded handle provides comfort. Hardened pins hold chain to tool , even if you unscrew a stubborn gear.