Got a brake which needs shortening? You'll need to get yourself an Olive & Connector to put the brake hose back into your brake lever.

There are two types of olive & hose inserts:

Standard:
These olives and inserts fit all standard size avid/SRAM hoses, but won't work on the newest models.

These fit all old avid brakes and older models of SRAM brakes. These WILL NOT fit brakes with Stealth-A-Majig fittings. You can identify Stealth-A-Majig fitting brakes by thoroughly looking over the lever and seeing if it says "Stealth-A-Majig" somewhere, if not this is your best bet. They are not backwards compatible.

Stealthmajig:
Stealthmajig compatible Olive and hose inserts are required for Stealthmajig type lever brakes. They can also be used on older Avid and Sram brakes. Whilst they are more expensive, their advantage lays in re-usability and ease of use. A T8 torx wrench is required to screw this in.

If you are cutting your brake hose it's worth having a hose clamp to help out. You can grab one here.