# Stock sources

> Sell multiple variants from a single central stock measured in weight, length or volume.

A stock source is a base product whose stock you track in a unit of measure such as weight, length or volume. From this single source you sell multiple variants. ShopLinkr automatically calculates how much is available per variant.

### When should you use this?

Stock sources are meant for products whose variants only come into being when they are filled or picked. For example:

- Dog food that you sell in bags of 500 grams, 1 kilo and 5 kilos

- Fabric that you sell per 50 cm, 1 meter or 3 meters

- Perfume that you decant into bottles of 50 ml, 100 ml and 250 ml

- Cable that you sell in lengths of 2, 5 and 10 meters

Do you sell variants that are produced in advance and stored separately (for example pallets of ready-made bottles of shampoo)? Then you manage those as individual products, not as a stock source.

### Example

You have 100 kilos of dog food as a stock source and sell variants of 500 grams and 1 kilo:

| Situation             | Source stock | 500g variant | 1kg variant |
| --------------------- | ------------ | ------------ | ----------- |
| Start                 | 100 kilos    | 200 units    | 100 units   |
| After selling 1x 1kg  | 99 kilos     | 198 units    | 99 units    |
| After selling 1x 500g | 98.5 kilos   | 197 units    | 98 units    |

With each sale the right amount is deducted from the source stock and all variants are recalculated automatically.

### Setting it up

1. Go to **Products** and open the product you want to use as the source.

2. Enable **Stock source** and choose the unit of measure (weight, length or volume).

3. Link variants and enter the amount for each variant (for example 500 grams or 1 kilo).

4. Click **Save**.

The stock of all variants is automatically synced with your sales channels.

### Pre-produced variants

You can also produce variants in advance from the source. This is handy for variants that sell frequently. For example: you produce 10 bags of 100 grams from your source of 100 kilos. 1 kilo is deducted from the source stock and the variant gets its own stock of 10 units.

- When a sale comes in, the pre-produced stock is used first.

- Once that runs out, you are prompted to produce from the source during [picking](/en/support/working-with-pick-lists).

### Returns and cancellations

- **Returns**: the stock is added to the variant, not to the source. This keeps the variant stock accurate.

- **Cancellations before shipping**: the reservation lapses and the amount is returned to the source stock.

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Bron: https://shoplinkr.com/en/support/stock-sources