A custom rubber part is quoted from three things: its shape, its compound and how many you need. The more of these we can see in your first message, the faster the quote comes back and the fewer questions follow.

Start with what you have

A drawing (PDF, DWG, DXF or STEP). The quickest route. Include the dimensions, tolerances and any hardness or compound noted on it.
The old part. Common for replacements and imported machines. We measure it and match it; if it is worn, tell us which faces are worn so we do not copy the wear.
A photo beside a ruler. Enough to start for simple parts such as gaskets, washers and pads. Add the key sizes in your message.

Drawings and samples are used only to quote and make your parts.

The five details that decide the quote

Size and shape: outside and inside sizes, thickness, holes and any profile.
What the part touches: water, oil, fuel, steam, chemicals or sunlight, and the temperature.
Movement: static gasket, moving seal, flexing diaphragm or a part under load.
Quantity: how many now, and how many per month or per year. Repeat volume changes the tooling decision.
Tolerances or standards: only where your drawing or customer specifies them.

Why quantity matters

Most moulded parts need a mould. For a new part we make a sample mould first; once the sample is approved, production follows in repeat batches. A realistic monthly figure lets us suggest the right mould for the volume.