Dongzheng is specialized in the production of GFCI(Ground-Fault Interrupters),dimmer,as well as some related products: wall switches,standard receptacle,metallic outlet boxes etc. Our Products have get the approval of UL, GFCI: UL(No.KCXS.E231858),CUL(No. KCXS7.E231858 )and Dimmer: UL(No. E250009). Moreover, Our products are also under the protection of USA patent No.ZL 02 351583.X and practical new-type patent No.ZL02 2 56638.4.Now we take American and canadian Markets as the main target ,with premium quality and competitive prices our GFCIs and dimmers are quite popular with the clients in these markets. this item is 4 wire flush dryer receptacle certificate: UL (NO. E250396) 30A, 125/250V cu or cu-clad wire only wire size:AWG#10--#4