SD:M3A1 HT

 is a United States Support and Transport unit.

Overview
M3A1 HT is a improved version of M3 HT with a improved M49 machine gun ring mount over the right hand front seat along with a number of drive train, engine, and stowage improvements. These along with M3 HT were the primary mounts of the Armored Infantry Battalions of the Armored Division. M3 equipped with M2 machine guns were issued to Platoon and Company Headquarters' Half-track along with Arm. LMG Rifles's half-track. 1st Infantry Division was issued M3A1 to serve as prime movers and light armor on the beach.