Tekmar M3057 O-Ring Kit for 1-1/2" to 2" Brass Valves The O-Ring Kit M3057 is a seal replacement kit for the tekmar 3-Way and 4-Way Brass Mixing Valves from 1-1/2" thru to 2". The kit includes a small o-ring, a medium o-ring (indicated with a white paint mark) and a large o-ring. All of the o-rings are lubricated with silicone grease. These o-rings are needed if a valve shaft is leaking or to reseal after opening up for maintenance.