The VR8200H2151 is a 1/2 x 1/2 SLOW OPENING 24 volt gas control for use in a standing pilot application. 

The carton contains on each -- 1/2 x 3/8 bushing, 3/4" block type flange kit, conversion kit from Natural to LP gas

Capacity of the valve with a 1" pressure drop through the body is 130,000 Btu/h 

Operating range  0 - 175f