diff --git a/src/uint.rs b/src/uint.rs
index b28583d..27b262f 100644
--- a/src/uint.rs
+++ b/src/uint.rs
@@ -7,6 +7,9 @@
 
 use uint::construct_uint;
 
+construct_uint! {
+    pub struct U320(5);
+}
 construct_uint! {
     pub struct U256(4);
 }
@@ -14,11 +17,17 @@ construct_uint! {
     pub struct U192(3);
 }
 
+
 #[allow(dead_code)]
 pub const fn to_u256(n: u128) -> U256 {
     U256([n as u64, (n >> 64) as u64, 0, 0])
 }
 
+// #[allow(dead_code)]
+// pub const fn to_u320(n: U256) -> U320 {
+//     U320([n as u64, (n >> 64) as u64,0,0])
+// }
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -68,4 +77,13 @@ mod tests {
             assert_eq!(from, back);
         }
     }
+
+    #[test]
+    fn test_u320_methods() {
+            let _max = U320::MAX;
+            let _from = U320::from(10);
+            let zero = U320::zero();
+            let is_zero =zero.is_zero();
+            assert!(is_zero);
+    }
 }