They were later modified by adding another radio set. It was equipped with a No. 19 radio set. It also held a SCR 508 radio set. The No. 19 radio set was carried. He also received the R-123M radio set for communication. For external communications it was intended to equip all vehicles with a radio set. Dial Tone built his own crystal radio set when he was ten. The cockpit was furnished with oxygen apparatus as well as a radio set for communication. The vehicle carried a No. 19 radio set. The commander's station is equipped with an R-123M radio set. On top of the radio set was a Type 3 reflector compass for precise navigation. The R-113 radio set was replaced by a R-123 radio set. The inexpensive radio set sold for $7, making it affordable to the masses. Also fitted is an R-123M radio set and an R-124 intercom. Some also had a No. 11 or No. 19 radio set.