Mercury Outboard 115hp Temperature Sender Sensor 78799 1 78799 2 100hp 125hp 3hp they changed the designs a

they changed the designs a few times

There will be 8 Splines if it is this style of gearcase

0L 4cyl applications for Pre-Alpha/R/MR/ALPHA ONE Gen 1

0L & 350 5

Great for a  spare

Mercury Outboard 115hp Temperature Sender Sensor 78799 1 78799 2 100hp 125hp 3hp they changed the designs aRemoved from a Mercury Outboard 115hp (S N OG240680) Inline 4 cylinder 2 Stroke Part #'s Temperature Sender: 78799 1,(Ring Terminal) may also work for this (78799 2) Item Condition and Notes: Good Working Condition Please Inspect Pictures for condition Yours should look like this one. Please ask if you are unsure if this part will work for you. Please send model and serial number. You will receive what is in the pictures. Please inspect pictures