Promax SQ-1 Crank Arm Set - 155mm, Square Taper JIS Spindle Interface. Made from the finest cold forged and CNC-machined 6061-T6 aluminum alloy Fits 5-bolt, 110 BCD chainrings 155mm length Bought for my son then COVID happened. He outgrew before I got a chance to use them. Just stayed in box until now. Thanks for interest.