Did some sleuthing on the net and came up with two possibilities. First, is that is the model number of an Asus drive 4816a which is actually rated at 48 x 16 x 48. Second, is that it is a Benq drive and the model number is a variation on their 4816P. The A replaces the P indicating it was manufactured in Australia. Both explanations are plausible.
If it is an Asus drive I will be keeping it and if it is a Benq it goes back. I would rather not go through the trouble of opening and installing it. Hoping somene has done that already and can enlighten me. So is it a Benq or an Asus? Thanks.