Sheet steel door for surface-mounted 4-row small distributor ALPHA SIMBOX - optimal down to the last detail. The small distributors ALPHA SIMBOX are designed for optimal use of space even in tight spaces. 1. The ALPHA SIMBOX XL offers generously dimensioned wiring spaces. 2. The small distributors are characterized by an extensive accessory package that is compatible with the flush-mounted distributor/hollow-wall distributor (terminals, cover strips, door lock).