Design and Build:
The Bird D636 was designed with a compact form factor, measuring 105 x 45.6 x 12.2 mm (4.13 x 1.80 x 0.48 in) and weighing only 98.4 grams (3.46 oz). This lightweight build would have made it an easily portable device, fitting comfortably in bags and most pockets. It utilized a Mini-SIM card, typical for the phones of its time. The casing was designed to be sleek and simple, available in a classic black color.