diff --git a/tclcheck.py b/tclcheck.py
index 5092a01..20368fb 100755
--- a/tclcheck.py
+++ b/tclcheck.py
@@ -12,12 +12,17 @@ fc.cltp  = 10
 fc.serid = "3531510"
 #fc.osvs  = "7.1.1"
 
+dp = tcllib.DefaultParser(__file__)
+dp.add_argument("prd", nargs="?", default="AAM481")
+dp.add_argument("fvver", nargs="?", default="PRD-63117-011")
+args = dp.parse_args(sys.argv[1:])
+
 if len(sys.argv) == 3:  # python tclcheck.py $PRD $FV = OTA delta for $PRD from $FV
-    fc.curef = sys.argv[1]
-    fc.fv = sys.argv[2]
+    fc.curef = args.prd
+    fc.fv = args.fvver
     fc.mode  = fc.MODE_OTA
 elif len(sys.argv) == 2:  # python tclcheck.py $PRD = FULL for $PRD
-    fc.curef = sys.argv[1]
+    fc.curef = args.prd
     fc.fv = "AAA000"
     fc.mode = fc.MODE_FULL
     fc.cltp  = 2010
diff --git a/tclcheck_allota.py b/tclcheck_allota.py
index 4b0aa2f..6c712ae 100755
--- a/tclcheck_allota.py
+++ b/tclcheck_allota.py
@@ -15,11 +15,14 @@ fc.serid = "3531510"
 fc.mode = fc.MODE_OTA
 fc.cltp  = 10
 
-force_ver = False
-force_ver_text = ""
-if len(sys.argv) > 1:
-    force_ver = sys.argv[1]
-    force_ver_text = " from {}".format(force_ver)
+dp = tcllib.DefaultParser(__file__)
+dp.add_argument("forcever", nargs="?", default=None)
+args = dp.parse_args(sys.argv[1:])
+
+if args.forcever is not None:
+    force_ver_text = " from {}".format(args.forcever)
+else:
+    force_ver_text = ""
 
 print("List of latest OTA firmware{} by PRD:".format(force_ver_text))
 
@@ -27,8 +30,8 @@ with open("prds.txt", "r") as f:
     for prdline in f:
         prdline = prdline.strip()
         prd, lastver, model = prdline.split(" ", 2)
-        if force_ver != False:
-            lastver = force_ver
+        if args.forcever is not None:
+            lastver = args.forcever
         try:
             fc.reset_session()
             fc.curef = prd
diff --git a/tclcheck_findprd.py b/tclcheck_findprd.py
index 41512fc..40ecece 100644
--- a/tclcheck_findprd.py
+++ b/tclcheck_findprd.py
@@ -19,6 +19,18 @@ fc.mode = fc.MODE_FULL
 #fc.cltp  = 10
 fc.cltp  = 2010
 
+dp = tcllib.DefaultParser(__file__)
+dp.add_argument("tocheck", nargs="?", default=None)
+dp.add_argument("-f", "--floor", dest="floor", nargs="?", type=int, default=0)
+dp.add_argument("-c", "--ceiling", dest="ceiling", nargs="?", type=int, default=999)
+args = dp.parse_args(sys.argv[1:])
+
+floor = args.floor
+ceiling = args.ceiling + 1
+if ceiling < floor:
+    print("Invalid range!")
+    raise SystemExit
+
 print("Valid PRDs not already in database:")
 
 with open("prds.txt", "r") as afile:
@@ -30,21 +42,23 @@ with open("prds.txt", "r") as afile:
         for key, value in prdc.items():
             prddict[key].append(value)
 
-if len(sys.argv) > 1:
+if args.tocheck is not None:
     prdkeys = list(prddict.keys())
     for k in prdkeys:
-        if k != sys.argv[1]:
+        if k != args.tocheck:
             del prddict[k]
-
+    if not prddict:
+        prddict[args.tocheck] = []
 
 for center in sorted(prddict.keys()):
     tails = [int(i) for i in prddict[center]]
-    total_count = 1000 - len(tails)
+    safes = [g for g in range(floor, ceiling) if g not in tails]
+    if floor in tails:
+        floor = safes[0]
+    total_count = len(safes)
     done_count = 0
     print("Checking {} variant codes for model {}.".format(total_count, center))
-    for j in range(0, 1000):
-        if j in tails:
-            continue
+    for j in safes:
         curef = "PRD-{}-{:03}".format(center, j)
         done_count += 1
         print("Checking {} ({}/{})".format(curef, done_count, total_count))
diff --git a/tclcheck_findver.py b/tclcheck_findver.py
index bbac1c7..0c579d2 100644
--- a/tclcheck_findver.py
+++ b/tclcheck_findver.py
@@ -13,18 +13,15 @@ fc = tcllib.FotaCheck()
 fc.serid = "3531510"
 fc.mode = fc.MODE_OTA
 
-if len(sys.argv) < 2:
-    print("Syntax: {} PRD [STARTVER] [ENDVER]".format(sys.argv[0]))
-    sys.exit()
+dp = tcllib.DefaultParser(__file__)
+dp.add_argument("prd")
+dp.add_argument("startver", nargs="?", default="AAA000")
+dp.add_argument("endver", nargs="?", default="AAZ999")
+args = dp.parse_args(sys.argv[1:])
 
-start_ver = "AAA000"
-end_ver = "AAZ999"
-if len(sys.argv) >= 2:
-    fc.curef = sys.argv[1]
-if len(sys.argv) >= 3:
-    start_ver = sys.argv[2]
-if len(sys.argv) >= 4:
-    end_ver = sys.argv[3]
+fc.curef = args.prd
+start_ver = args.startver
+end_ver = args.endver
 
 print("Valid firmwares for model {} (between {} and {}):".format(fc.curef, start_ver, end_ver))
 
diff --git a/tcllib.py b/tcllib.py
index 9ca8a33..66c547d 100644
--- a/tcllib.py
+++ b/tcllib.py
@@ -2,6 +2,7 @@
 
 # pylint: disable=C0111,C0326
 
+import argparse
 import base64
 import binascii
 import hashlib
@@ -35,6 +36,11 @@ def make_escapes_work():
             colorama.init()
 
 
+class DefaultParser(argparse.ArgumentParser):
+    def __init__(self, appname):
+        super().__init__(prog=appname.replace(".py", ""), epilog="https://github.com/mbirth/tcl_ota_check")
+
+
 class FotaCheck:
     VDKEY = b"eJwdjwEOwDAIAr8kKFr//7HhmqXp8AIIDrYAgg8byiUXrwRJRXja+d6iNxu0AhUooDCN9rd6rDLxmGIakUVWo3IGCTRWqCAt6X4jGEIUAxgN0eYWnp+LkpHQAg/PsO90ELsy0Npm/n2HbtPndFgGEV31R9OmT4O4nrddjc3Qt6nWscx7e+WRHq5UnOudtjw5skuV09pFhvmqnOEIs4ljPeel1wfLYUF4\n"
     CKTP_CHECKAUTO = 1