E. F. Johnson Company Product. 5100 Series Digital Project 25 Yellow Portable Handset. Material: metal, plastic. Size: 2 1/4" x 13" x 1 3/4" H. Description: yellow and black plastic and metal case; digital screen at top; push buttons: F1, F2, F3, F4, 1-9, 0, *, #; speaker at bottom; removable battery pack on back; antenna attached at top; two dials at top; four push buttons on left side; clip at back.