Smoothing Air Hammer Tool Kit Pneumatic Chisel Bits Accessories Including 3pcs 0.401'' (10mm) Shank Air Hammer and 1pc Spring Features: Material: alloy steel Type: hammer bits Sizes: -- Oval-shaped Air Hammer bit: 176 * 25mm (6.93 * 0.98 inch) -- 2 Pcs Flat Head Air Hammer bits: 100 * 30mm (4.0* 1.18 inch); 80 * 35mm (3.14 * 1.37 inch) -- Spring: 28* 26mm (1.10* 1.02 inch) Package included: 3x Hammer bits 1x Spring Note: 1.Please allow 1-2cm errors due to manual measurement. 2.The head of the hammer bits include corve and flat head. 3.Due to the different image angles, some images may not display of the clear head shape, please understand, thank you! （The longest hammer head is spherical shape,others hammer is flat shape.） 4. The bit installed in the pneumatic sewing machine, need to connect the air compressor to use.can replace the head to use.