Unidentified Telephone

I have just acquired a telephone whose keys are on the phone base, not on the handset. This frees both hands, because I can tuck the handset under my chin while talking, without the risk of accidentally cutting off the conversation.

Unfortunately, there was no manual or other instruction information, and I don't know how to set up the memory. The only identification is on the bottom of the base which provides the model number HT-916, and the logo "ETL" surrounded by a circle. The handset is slim. The instrument was made in China.

There are 6 functions: Store, Auto, Hold, Flash, Redial, and SP-phone. There are also 3 speed dial (?) keys, M1, M2, & M3. There is a small window above the M1, etc keys; I don't know whether this relates to the Flash function, or perhaps Caller ID. The keys are oversized, for users with low vision.

Can anyone give me a clue as to the manufacturer or distributor, and/or information about storing numbers, and using the other functions? Redial is obvious, and SP-phone works properly. I have no idea what "Auto" is.