The BMW E92 M3 Driveshafts are based on a tripod joint instead of the OEM CV joint. 
If you are in the need of custom driveshafts, a measurement sheet will need to be filled in. If currently OEM driveshafts are installed (no modifications made to chassis/suspension), standard length driveshafts can be supplied. 
We can supply a dedicated BMW measurement shaft to avoid wrongly measured lengths. Custom driveshaft lengths have an additional lead time of 2-3 weeks. 
There is no price difference in custom or OEM length driveshafts.
Replaces BMW OEM Number: 33212283457 – Output shaft left
Benefits of the KMP Tripod driveshafts:
• Higher strength
• Less friction
• Lower temperature
• Easy to service