Abstract: A double-strung game racquet includes a headframe with two parallel playing surfaces, each forming an area at least as large as an area bounded by an external perimeter of the headframe. The playing surfaces are formed using two strings, a horizontal tensioned string to form horizontal components of the two surfaces interwoven with a vertical tensioned string to form vertical components of the two surfaces. The headframe has two rows of corresponding holes formed therein, and each string is wrapped around the headframe in such a way that the strings repeatedly pass over an outside peripheral edge on a first side of the headframe, across to an opposite side of the headframe, over an outside peripheral edge of the opposite side, in through a hole, out through an adjacent hole, over another outside peripheral edge of the opposite side, and across to the first side.

Abstract: A universal guide for an electric drill includes a transparent elongated L-shaped member with two mutually perpendicular faces. Each face has two parallel long edges and two short edges, and they share a common long edge. For each face, one of the two short edges is a perpendicular edge and the other of the two short edges is an angled edge in which the perpendicular edges are perpendicular to the long edges, and the common edge is formed such that the perpendicular edges are mutually adjacent to each other and the angled edges are mutually adjacent to each other. Magnetic areas are formed on surfaces of each of the faces. Level indicators are attached to each face perpendicular to the common long edge and to the common long edge in a direction perpendicular to the perpendicular level indicators. At least one long edge is ruled and guide lines are marked on the faces in a direction parallel to the long edges.

Abstract: A zipper including a pair of rows of teeth, a catch for joining/unjoining the two rows of teeth as the catch is moved relative to the two rows of teeth; a pair of flaps disposed underneath the two rows of teeth, respectively, such that as the catch moves relative to the two rows of teeth to join the two rows of teeth together, the pair of flaps overlap each other, thereby preventing extraneous material from being entangled in the catch and the two rows of teeth.