The standard heatsink lengths for TO-126 heatsinks are 25mm (single clip) and 40mm (2 clips).
C Series is offered in standard 25, 50, and 75mm lengths for TO-220 and TO-247 devices (30, 58, and 85mm for TO-264 packages). Designers also benefit from the opportunity to specify exactly which length, number of clips and surface finish they require. Custom lengths and clip quantities are also available.