It's a great product to start off with for simracing since you can extend this later on to add a seat.(Seat extension unknown if it fits any seat extension but there are screws for when adding)not an expert but i used a tape measure and the measurement for the extension hole is 1.2"(don't quote me on that)Minor issue is that 3 screws are too short and one missing screw for the shifter mount.(Check photo for reference)Overall the build quality is amazing and i can see myself using this for years on end. Seller please confirm the size needed for an extension seat Ty!