Abstract: A removable threshold (18) wherein a first sidewall (20) and a second sidewall (22) are joined to a top section (48). The first sidewall (20) has a lower lateral edge (26) and terminal portions (28 and 30) that form radiused corners (68 and 70). The second sidewall (22) has a lower lateral edge (34) and terminal portions (36 and 38) that form radiused corners (76 and 78). Top section (48) has ends (54 and 56) that define radiused edges (84 and 86). Edges (84 and 86) are flush with the edges of terminal portions (28, 30, 36 and 38) and a gasket (62) is secured continuously to threshold (18) along lower lateral edges (26 and 34), terminal portions (28, 30, 36 and 38) and edges (84 and 86) to provide a seal between threshold (18) and a fixture (10).