Diamond Group By Valterra Square 30 Amp Standard Cover White. Diamond Group's square standard 30 Amp cover will replace broken or old receptacle covers. This receptacle cover is available in white or ivory and is made with durable plastic construction for long-lasting use. Features of Diamond Group By Valterra Square 30 Amp Standard Cover 30 Amp standard cover Shape: Square Color: White Durable plastic construction Meet OEM Standards Package Contents: Diamond Group By Valterra Square 30 Amp Standard Cover Diamond Group DG52399PB: By Valterra Square 30 Amp Standard Cover White