Not to be impolite....
But it should feel like you would expect a human's to feel, but a bit bigger. Not knowing your age or gender - all I can tell you is that if you don't know what that should feel like, go talk to a woman - guys get all squeemish when one talks about feeling for nuts in preparation for gelding. Take my word on that! My hubby banned the subject from the house! If you think you might just be feeling flesh, you probably are.
So... having dealth with a colt who did not want them to come off and had every intention of keeping one of them, let me tell you what you are in for if you don't two...
First and foremost, some colts don't drop both until two, especially some of the gaited breeds - don't ask me why when my Arab colt had both down at five months. The Saddlebred at 22 months only had one. So give them some time, just in case they are a late dropper, while you save up your cash.
The next thing is to find a really really good vet. Do your research and ask for references for people who have had this surgrey done. It is a really complicated word that I am not even going to try to spell, but it starts with a crypt and go on for 15 or 20 more letters after that. No matter what your finances are, throw out the lowest two estimates.
This surgery is expensive for a reason. In this area, the vets want to keep the colt under 24 hour care for between one to four days - at $800 a day! Do not, repeat, do not let them send him home the same day!!! That vet is a quack and you will be lucky if your horse lives through it - mine did, but only barely!
The reason for the hospital stay is that this is abdominal surgery where they usually leave drainage slits open. My colt, at 22 months, was knocked out cold for two hours for the surgery, then we were sent home four hours after that - with blood and clear fluid dripping from the incisions. We followed all care instructions, stall rest for one day, trurn out by himself after that.
Three days later, with no warning, he fell over in his pasture. Somehow we got him in a trailer and back to the vet for treatment of the massive infection. His fevor was 105. Two days hospitalized and he came home on massave doses of antibiotics for 20 more days before his blood test came back clean of infection. My low cost $800 surgery cost me an additonal $4,000 to save my horse.
As for the two incision points that were left to 'drain' - well drain they did, for the next five years!!!
I hope this helps and does not traumatize... the good news is that my horse is fine and doing great.