Fits normal size Champion 4 inch diameter filter. Supports the filter for oil drain back into the casing. If you are careful, you can pull the filter out with a finger, hold it over the case, install the support and place the filter on it without spilling a drop. No other pans for oil filter draining required. After the oil drains for a day it doesn't make a mess during cutting and inspection. Plastic material resists oils, fuel, acetone and paint thinners. Flexible enough to be stepped on without breakage. Tested up to 10 degree offset from vertical with oil overload test with no leakage. See development write up.