The 10 x 12" sef coil measures 9 1/2 x 12",the Eleven inch Pro coil actually measures 10 1/2" tip 2 tip, the 5 x 10" Joey I think measures 4 1/2 x 9 1/2" ,and the 8" minelab coil measures 7 1/4"tip 2 tip.....the 5" sun-ray measures 5 3/4".
These are DD coils which detect almost ? the total length,and about an inch wide....Which would mean out of the five mentioned,,,the 5" sunray @ 5 3/4"would have the best separation,then the 8",,@ 1"x 7 1/4",,,,,,then the Joey @ 1" x 9 1/2",,,,then the Pro coil @ 1"x 10 1/2"..Then the 10 x 12" sef coil woul cover the most ground,and have the most chance of being effected by 2 or more target simotainiously .........I have used all five coils,and find the pro coil can get the job done in high trash areas,but for Most trashy areas the 8" is the better option ,and you can move around a little faster.............In Insane trashy areas,,,,,,,,I use my 5" sunray...But most of the time in trashy areas I just use the 8",and when you have say a clearer ten foot area...You can move threw it fairly fast ,,,till you have to slow down in the next trashy area again.
I purchased my 8" for hunting wooded areas,and moving faster (than the Pro) threw trashy areas.....My Friend let me use the 5 x 10 joey while hunting the woods a couple times,and it's a great (woods ) coil.
I would love to be able to own the coils that would cover most all the bases.....Which would be....5",8", 5x10",10x12",and 12 x 15"....Along with the pro......But I will settle for what I have, which is the 5",8",The Pro,and the 10 x 12"..sef...........which measures 9 1/2 " x 12",and covers an 1 1/2" more than the pro.........
My buddy bought the 12 x 15 ,,,when I got my 10 x 12...........Three of us E-Trac users will be hunting Parks together this spring....My bud is going to use his 12 x 15,while I use the 10 x 12,,,,,and my other bud will us his Pro coil.........We will compare the sef's to the Pro coil ,before making any further Sef purchases.
Before you purchase another coil. Find out the True dimensions,so you can compare with sun-ray / coil-tech /Minelab, or digitech? sefs.