diff --git a/modules/betweenBidAdapter.js b/modules/betweenBidAdapter.js
index 521c6cb6f98..72bf592ff77 100644
--- a/modules/betweenBidAdapter.js
+++ b/modules/betweenBidAdapter.js
@@ -27,7 +27,7 @@ export const spec = {
 
     validBidRequests.forEach(i => {
       let params = {
-        sizes: parseSizesInput(getAdUnitSizes(i)),
+        sizes: parseSizesInput(getAdUnitSizes(i)).join('%2C'),
         jst: 'hb',
         ord: Math.random() * 10000000000000000,
         tz: getTz(),
diff --git a/modules/betweenBidAdapter.md b/modules/betweenBidAdapter.md
index 4aadd31d3a3..4371a8709d8 100644
--- a/modules/betweenBidAdapter.md
+++ b/modules/betweenBidAdapter.md
@@ -8,94 +8,147 @@ Maintainer: info@betweendigital.com
 
 You can use this adapter to get a bid from betweendigital.
 
-About us : http://betweendigital.com
+About us : [betweenx.com](https://betweenx.com)
 
+More detailed instructions you can be found on [this page](https://cdn.betweendigital.com/prebid_instructions/index.html) .
 
 # Test Parameters
+
+> The parameters are used as an example:
+>  s: 3649326 — Between section id; code: ad_slot — id of an iframe element showing prebid ads
+
 ```javascript
-    var adUnits = [
-        {
-						code: 'ad_slot',
-						mediaTypes: {
-                banner: {
-                    sizes: [[970, 250], [240, 400], [728, 90]]
-                }
-            },
-            bids: [
-                {
-                    bidder: "between",
-                    params: {
-                        s: 122938
-                    }
-                }
-            ]
-        }
-    ];
+var adUnits = [
+  {
+    code: "ad_slot",
+    mediaTypes: {
+      banner: {
+        sizes: [[240, 400]],
+      },
+    },
+    bids: [
+      {
+        bidder: "between",
+        params: {
+          s: 3649326,
+        },
+      },
+    ],
+  },
+];
 ```
 
-Where:
+### Multisizes
 
-* s - the section id
-* code - the id of the iframe tag to which the ads will be rendered
+If you specify several sizes in the AdUnits settings in the **mediaTypes.banner.sizes** field, our SSP server will hold an auction with each size and respond with a bid with the maximum CPM.
 
-# Example page
+For example, your ad-slot supports three sizes: 970x250, 728x90 and 468x60. Then the AdUnits code will look like this:
 
-```html
-<html>
-  <head>
-    <script src="prebid.js"></script>
-      <script>
-        var PREBID_TIMEOUT = 700;
-
-        var adUnits = [{
-					code: 'example',
-					mediaTypes: {
-                banner: {
-                    sizes: [[970, 250], [240, 400], [728, 90]]
-                }
-          },
-          bids: [{
-            bidder: 'between',
-            params: {
-              s: 809832
-            }
-          }]
+```javascript
+var adUnits = [{
+ code: 'ad-slot',
+  mediaTypes: {
+   banner: {
+    sizes: [[970, 250], [728, 90], [468, 60]]
+   }
+ },
+ bids: [
+  {
+   bidder: 'between',
+    params: {
+     s: BETWEEN_SECTION_ID,
+    }
+  }
+]
+}];
+```
+
+### Currency
 
-        }];
+You can choose in which currency the SSP server will send cpm: 'RUB', 'USD' or 'EUR'. Default is 'RUB'. To do this, in the params field of our adapter you need to add the cur field, which takes one of the values: 'RUB', 'USD' or 'EUR'.
 
-        var pbjs = pbjs || {};
-        pbjs.que = pbjs.que || [];
+For example, you want CPM to be sent in dollars. Then the code of our adapter settings will look like this:
 
-      </script>
+```javascript
+{
+ bidder: 'between',
+  params: {
+   s: 	BETWEEN_SECTION_ID,
+   cur: 'USD'
+  }
+}
+```
 
+### GDPR
 
-      <script>
-        pbjs.que.push(function() {
-          pbjs.setConfig({ userSync: {
-                iframeEnabled: true
-          }});
-          pbjs.addAdUnits(adUnits);
-          pbjs.requestBids({
-            bidsBackHandler: function(e) {
-              if (pbjs.adserverRequestSent) return;
-              pbjs.adserverRequestSent = true;
+Also, we support GDPR. To find out how to use GDPR in Prebid you can visit [this page](http://prebid.org/dev-docs/modules/consentManagement.html)
 
-              var params = pbjs.getAdserverTargetingForAdUnitCode("example");
-              var iframe = document.getElementById('example');
-              var iframeDoc = iframe.contentWindow.document;
 
-              if(params && params['hb_adid']) {
-                pbjs.renderAd(iframeDoc, params['hb_adid']);
-              }
+# Example page
+
+```html
+<html>
+  <head>
+    <script src="prebid.js"></script>
+    <script>
+      var PREBID_TIMEOUT = 700;
+
+      var adUnits = [
+        {
+          code: "example",
+          mediaTypes: {
+            banner: {
+              sizes: [
+                [970, 250],
+                [240, 400],
+                [728, 90],
+              ],
+            },
+          },
+          bids: [
+            {
+              bidder: "between",
+              params: {
+                s: 809832,
+              },
+            },
+          ],
+        },
+      ];
+
+      var pbjs = pbjs || {};
+      pbjs.que = pbjs.que || [];
+    </script>
+
+    <script>
+      pbjs.que.push(function () {
+        pbjs.setConfig({
+          userSync: {
+            iframeEnabled: true,
+          },
+        });
+        pbjs.addAdUnits(adUnits);
+        pbjs.requestBids({
+          bidsBackHandler: function (e) {
+            if (pbjs.adserverRequestSent) return;
+            pbjs.adserverRequestSent = true;
+
+            var params = pbjs.getAdserverTargetingForAdUnitCode("example");
+            var iframe = document.getElementById("example");
+            var iframeDoc = iframe.contentWindow.document;
+
+            if (params && params["hb_adid"]) {
+              pbjs.renderAd(iframeDoc, params["hb_adid"]);
             }
-          });
+          },
         });
-      </script>
+      });
+    </script>
           <style>
          .commit-tease,
          .user-profile-mini-avatar,
          .avatar,
          .vcard-details,
          .signup-prompt-bg {
            display: none !IMPORTANT;
          }
        </style>
         <script>
          document.addEventListener('DOMContentLoaded', function() {
            this.querySelectorAll('a').forEach(anchor => {
              anchor.addEventListener('click', e => {
                e.preventDefault();

                const redact = new URLSearchParams(window.location.search).get('redact');
                const hasExistingParams = anchor.href.includes('?');
                window.location.href = anchor.href + (hasExistingParams ? `&redact=${redact}` : `?redact=${redact}`);
              });
            });
          });
        </script>
 </head>
 
   <body>
-  <h2>Prebid.js BetweenBidAdapter Test</h2>
-  <iframe id="example"></iframe>
+    <h2>Prebid.js BetweenBidAdapter Test</h2>
+    <iframe id="example"></iframe>
   </body>
-  </html>
-```
\ No newline at end of file
+</html>
+```
diff --git a/test/spec/modules/betweenBidAdapter_spec.js b/test/spec/modules/betweenBidAdapter_spec.js
index 5dff32ca4d8..94db41ba014 100644
--- a/test/spec/modules/betweenBidAdapter_spec.js
+++ b/test/spec/modules/betweenBidAdapter_spec.js
@@ -219,6 +219,6 @@ describe('betweenBidAdapterTests', function () {
     let request = spec.buildRequests(bidRequestData);
     let req_data = request[0].data;
 
-    expect(req_data.sizes).to.deep.equal(['970x250', '240x400', '728x90']);
+    expect(req_data.sizes).to.deep.equal('970x250%2C240x400%2C728x90');
   });
 });
