diff --git a/Cargo.toml b/Cargo.toml
index a652a4b..3ea4fcb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,8 @@ categories = ["memory-management", "caching"]
 
 [dependencies]
 get-size-derive = { version = "^0.1.3", optional = true }
+tokio = { version = "^1", optional = true , features = ["sync", "time", "io-util"]}
+serde_json = { version = "^1", optional = true}
 
 [features]
 default = []
diff --git a/src/lib.rs b/src/lib.rs
index 65c3057..7e8f6d5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -53,8 +53,7 @@ use std::time::{Instant, Duration, SystemTime};
 #[cfg(feature = "derive")]
 #[cfg_attr(docsrs, doc(cfg(feature = "derive")))]
 pub use get_size_derive::*;
-
-
+use tokio::io::AsyncRead;
 
 
 #[cfg(test)]
@@ -140,9 +139,12 @@ impl<T> GetSize for PhantomData<T> {}
 impl GetSize for PhantomPinned {}
 
 impl GetSize for Instant {}
-impl GetSize for Duration {}
 impl GetSize for SystemTime {}
-
+impl GetSize for Duration {
+    fn get_stack_size() -> usize {
+        12
+    }
+}
 
 
 impl<'a, T> GetSize for Cow<'a, T>
@@ -334,6 +336,12 @@ impl<T> GetSize for Arc<T> where T: GetSize {
     }
 }
 
+impl GetSize for Arc<str> {
+    fn get_size(&self) -> usize {
+        std::mem::size_of::<usize>() + (&**self).get_size()
+    }
+}
+
 impl<T> GetSize for Option<T> where T: GetSize {
     fn get_heap_size(&self) -> usize {
         match self {
@@ -375,7 +383,11 @@ impl GetSize for String {
     }
 }
 
-impl GetSize for &str {}
+impl GetSize for &str {
+    fn get_size(&self) -> usize {
+        std::mem::size_of_val(*self)
+    }
+}
 
 impl GetSize for std::ffi::CString {
     fn get_heap_size(&self) -> usize {
@@ -448,3 +460,39 @@ impl<T> GetSize for Box<[T]> {
         total
     }
 }
+
+#[cfg(feature = "tokio")]
+impl<T> GetSize for tokio::sync::mpsc::UnboundedSender<T> {}
+
+#[cfg(feature = "tokio")]
+impl<T> GetSize for tokio::sync::mpsc::WeakUnboundedSender<T> {}
+
+#[cfg(feature = "tokio")]
+impl GetSize for tokio::time::Instant {}
+
+#[cfg(feature = "tokio")]
+impl GetSize for tokio::time::Interval {
+    fn get_size(&self) -> usize {
+        std::mem::size_of_val(self)
+    }
+}
+
+#[cfg(feature = "tokio")]
+impl <T: AsyncRead> GetSize for tokio::io::BufReader<T> {
+    fn get_size(&self) -> usize {
+        let inner = std::mem::size_of_val(self.get_ref());
+        let buf = self.buffer().len();
+        let pos = 1_usize;
+        let cap = 1_usize;
+        let seek_state = 9_usize;
+
+        inner + buf + pos + cap + seek_state
+    }
+}
+
+#[cfg(feature = "serde_json")]
+impl GetSize for serde_json::Value {
+    fn get_size(&self) -> usize {
+        std::mem::size_of_val(self)
+    }
+}
\ No newline at end of file
diff --git a/src/tests/mod.rs b/src/tests/mod.rs
index 3da0abd..4ad2af6 100644
--- a/src/tests/mod.rs
+++ b/src/tests/mod.rs
@@ -244,3 +244,10 @@ fn derive_newtype() {
     let test = TestNewType(0);
     assert_eq!(u64::get_stack_size(), test.get_size());
 }
+
+#[test]
+fn test_arc_str_size(){
+    let str_text = "a";
+    let arc: Arc<str> = Arc::from(str_text);
+    assert_eq!(arc.get_size(), std::mem::size_of::<usize>() + std::mem::size_of_val(str_text));
+}
\ No newline at end of file