It lets an eligible revoked driver keep driving on a restricted basis with a certified breath-testing device in each vehicle they operate. The DMV requires an SR-22 on file until the permit expires when the vehicle is registered in the driver's name only.
More detail
Eligibility depends on the specific revocation, which is why the DMV notice and, where the case warrants it, a lawyer are the right sources rather than general guidance. The DMV's permit page lists the pieces: an application, a certified court order where the permit rests on one, a certificate of installation for each vehicle the driver will operate, surrender of the license or a lost-license affidavit, and any other reinstatement requirements on the record. The permit itself is $45 plus a $5 surcharge. On insurance, the DMV's SR-22 page says the filing must stay on file until the permit expires when the vehicle is registered in the driver's name only, so for most car owners the sensible order is policy, then certificate, then permit application. A driver with no vehicle registered to them should check the DMV's online interlock eligibility tool for their own requirements. In this market the permit carries more weight than it might elsewhere: Sarpy County households connected to Offutt, Fremont commuters running US 275 into the metro, and second-shift workers in Columbus and Grand Island generally have no workable alternative to driving, so the permit is often the difference between keeping a job and not.