What’s the difference between the ECC-UHC and ECC-UMC Cutout Covers?
ECC-UMC - one cutout cover fits both porcelain and polymer cutouts

ECC-UM
The ECC-UM series are a universal cutout cover that fits porcelain and polymer type XS cutouts, 110, 125 and 150 BIL cutouts. The front of the cover is shorter than the ECC-UH series and an extension cannot be added. To add the extension to the front for added coverage see ECC-UMC. For porcelain cutouts install the pins one high and one low, as shown. For polymer cutouts install both pins in the lower two holes.
ECC-UHC - one cutout cover fits both porcelain and polymer cutouts

ECC-UH
The ECC-UH series are a universal cutout cover that fits porcelain and polymer type XS cutouts, 110, 125 and 150 BIL cutouts. The front of the cover is taller than the ECC-UM series and an extension cannot be added. To add the extension to the front for added coverage see ECC-UHC. For porcelain cutouts install the pins one high and one low, as shown. For polymer cutouts install both pins in the lower two holes.
ECC-10UC - one cutout cover fits both porcelain and polymer SMD-20 cutouts

ECC-10U
The ECC-10U series are a universal cutout cover design for S&C SMD 20 cutouts, porcelain and polymer. The ECC-10U does not have the capability to add an extension to the front for added coverage. See ECC-10UC for the capability to add an extension to the front. For FR rated material the part number would be ECC-10U-FR.
SC-1
Squirrel cover, for use with ECC-UHC and ECC-UMC cutout covers. The squirrel cover can be hot stick installed. Covers the slot in the back and up over the top of the cutout cover to help prevent squirrels from storing nuts inside the cutout cover. Available in FR, UL 94 5VA. Part number would be SC-1-FR when ordering separately. US Patent 10,566,166
SC-1-FR
Squirrel cover FR rated, for use with ECC-UHC-FR and ECC-UMC-FR cutout covers. When ordering the cutout cover and squirrel cover together part number would be ECC-UHCS-FR or ECC-UMCS-FR. The squirrel cover can be hot stick installed. Covers the slot in the back and up over the top of the cutout cover to help prevent squirrels from storing nuts inside the cutout cover. Part number would be SC-1-FR when ordering separately.
US Patent 10,566,166