diff --git a/README.md b/README.md
index 27f2ad9..28840bb 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,16 @@ $ boks apps dbms data
 +----------+     +----------+     +----------+
 ```
 
-Use `-a` to customize length of arrows, `-p` to customize padding.
+Use `-a` to customize arrow style, `-p` to customize padding length.
+
+e.g.
+
+```shell
+$ boks -a '--->' 'declarative query' 'optimized plan'
++-----------------------+    +--------------------+
+|   declarative query   |--->|   optimized plan   |
++-----------------------+    +--------------------+
+```
 
 ## Installation
 
diff --git a/bin/main.ml b/bin/main.ml
index 121676d..6411e9d 100644
--- a/bin/main.ml
+++ b/bin/main.ml
@@ -2,7 +2,7 @@ open Boks
 
 let usage_msg = "boks -p <padding size> -a <arrow size> <text1> [<text2>] ..."
 let padlen = ref 3
-let arrowlen = ref 3
+let arrow = ref "<--->"
 let texts = ref []
 
 let accept_text t =
@@ -10,12 +10,14 @@ let accept_text t =
 
 let speclist = [
   ("-p", Arg.Set_int padlen, "Padding size");
-  ("-a", Arg.Set_int arrowlen, "Arrow size");
+  ("-a", Arg.Set_string arrow, "Arrow");
 ]
 
 let () =
   Arg.parse speclist accept_text usage_msg;
   let padlen = !padlen in
-  let arrowlen = !arrowlen in
-  let texts = !texts in
-  boks ~padlen ~arrowlen texts
+  let arrow = !arrow in
+  let texts =
+    if List.is_empty !texts then ["moo"] else !texts
+  in
+  boks ~padlen ~arrow texts
diff --git a/boks.opam b/boks.opam
index 3b957d2..2f372e6 100644
--- a/boks.opam
+++ b/boks.opam
@@ -1,14 +1,14 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-synopsis: "A short synopsis"
-description: "A longer description"
-maintainer: ["Maintainer Name"]
-authors: ["Author Name"]
-license: "LICENSE"
-tags: ["topics" "to describe" "your" "project"]
-homepage: "https://github.com/username/reponame"
-doc: "https://url/to/documentation"
-bug-reports: "https://github.com/username/reponame/issues"
+synopsis: "Box maker in OCaml"
+description: "CLI tool to make boxes with text in OCaml"
+maintainer: ["Kaustubh M"]
+authors: ["Kaustubh M"]
+license: "MIT"
+tags: ["cli"]
+homepage: "https://github.com/nikochiko/boks"
+doc: "https://git.kaustubh.page/kaustubh/boks"
+bug-reports: "https://github.com/nikochiko/boks/issues"
 depends: [
   "ocaml"
   "dune" {>= "3.13"}
@@ -28,4 +28,4 @@ build: [
     "@doc" {with-doc}
   ]
 ]
-dev-repo: "git+https://github.com/username/reponame.git"
+dev-repo: "git+https://github.com/nikochiko/boks.git"
diff --git a/dune-project b/dune-project
index d5b41fd..c8038b6 100644
--- a/dune-project
+++ b/dune-project
@@ -20,4 +20,4 @@
  (synopsis "Box maker in OCaml")
  (description "CLI tool to make boxes with text in OCaml")
  (depends ocaml dune)
- (tags "cli"))
+ (tags ("cli")))
diff --git a/lib/boks.ml b/lib/boks.ml
index 9cd6935..60e8ed7 100644
--- a/lib/boks.ml
+++ b/lib/boks.ml
@@ -5,18 +5,14 @@ let bok_core padlen text =
   let padding = String.make padlen ' ' in
   Printf.sprintf "|%s%s%s|" padding text padding
 
-let arrow len =
-  Printf.sprintf "<%s>" (String.make len '-')
-
-let boks ?(padlen=3) ?(arrowlen=3) texts =
-  let conn = arrow arrowlen in
-  let conn_space = String.make (String.length conn) ' ' in
+let boks ~padlen ~arrow texts =
+  let conn_space = String.make (String.length arrow) ' ' in
   let boks_edge = String.concat
     conn_space
     (List.map (bok_edge padlen) texts)
   in
   let boks_core = String.concat
-    conn
+    arrow
     (List.map (bok_core padlen) texts)
   in
   Printf.printf "%s\n%s\n%s\n" boks_edge boks_core boks_edge
diff --git a/lib/boks.mli b/lib/boks.mli
index d6fa2da..0726e78 100644
--- a/lib/boks.mli
+++ b/lib/boks.mli
@@ -1 +1 @@
-val boks : ?padlen:int -> ?arrowlen:int -> string list -> unit
+val boks : padlen:int -> arrow:string -> string list -> unit