The FIT Shaft Gear Normal Locked from COSMO are specific shafts for the COSMO flights. These shafts do not contain a notch to press a normal flight into, but have a puzzle piece on the end that only fits into the cosmoflight by means of a click system. The shafts are available in different sizes and specify a numerical size. Shaft Dimensions: Size 1/13 mm, Size 2/18 mm, Size 3/24 mm, Size 4/28 mm, Size 5/31 mm, Size 6/35 mm, Size 7/38 mm, Size 8/42 mm .