diff --git a/99-usb-sync.rules b/99-usb-sync.rules
index 3c2aac8..b1d8fb4 100644
--- a/99-usb-sync.rules
+++ b/99-usb-sync.rules
@@ -1,10 +1,12 @@
 # rule to disable write cache for usb storage
 # requires hdparm to be installed
-ACTION=="add|change", KERNEL=="sd[a-z]", ENV{ID_USB_TYPE}=="disk", RUN+="/usr/bin/hdparm -W 0 /dev/%K"
+ACTION=="add|change", KERNEL=="sd[a-z]", ENV{ID_USB_TYPE}=="disk", RUN+="/usr/bin/hdparm -W 0 /dev/%k"
 #
 # rules to impose buffer limits on USB devices
 # requires kernel > 6.1
 # https://docs.kernel.org/admin-guide/abi-testing.html#abi-sys-class-bdi-bdi-strict-limit
 # https://docs.kernel.org/admin-guide/abi-testing.html#abi-sys-class-bdi-bdi-max-ratio
 # https://docs.kernel.org/admin-guide/abi-testing.html#abi-sys-class-bdi-bdi-max-bytes
-ACTION=="add|change", KERNEL=="sd[a-z]", ENV{ID_USB_TYPE}=="disk", RUN+="/usr/bin/echo 1 > /sys/block/%K/bdi/strict_limit",  RUN+="/usr/bin/echo 50 > /sys/block/%K/bdi/max_ratio", RUN+="/usr/bin/echo 16777216 > /sys/block/%K/bdi/max_bytes"
+# implemented using  /usr/bin/udev-usb-tweak.sh 
+# optional configuration in /etc/udev-usb-tweak/udev-usb-tweak.sh
+ACTION=="add|change", KERNEL=="sd[a-z]", ENV{ID_USB_TYPE}=="disk", RUN+=/usr/bin/udev-usb-sync.sh %k"
diff --git a/PKGBUILD b/PKGBUILD
index 01e1ba3..4a7952a 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -1,17 +1,25 @@
-# Maintainer: 
+# Maintainer: root.nix.dk
 pkgname='udev-usb-sync'
-pkgver=0.1
-pkgrel=1
-pkgdesc='Disable writecache when USB storage device is plugged'
+pkgver=0.3
+pkgrel=6
+pkgdesc='Fine tune write cache when USB storage device is plugged'
 arch=('any')
 url='https://codeberg.org/wonky/udev-usb-sync'
 license=('MIT')
 depends=('hdparm')
 provides=("${pkgname}")
-source=('99-usb-sync.rules')
-sha256sums=('ed0253bbbd5b64529efd752978ba17176e3ff23d3f7f220bbacd3fa3a3691df9')
+backup=("etc/${pkgname}/${pkgname}.conf")
+install=${pkgname}.install
+source=('99-usb-sync.rules' 'udev-usb-sync.sh' 'udev-usb-sync.conf')
+sha256sums=('39e714df856c8d47fe14365b854b9a1b36ed3afa300383d8329452394a01a1c4'
+            '2669e043722b33009798c8c30f48414e1eaad0f001631587f502b19a2f11feb7'
+            'bc902da2c453355e1dbc3a970a564daf71d41c6278dc771a930aa3badb90e453')
 
 package() {
     install -d -m755 $pkgdir/etc/udev/rules.d
-    cp ${startdir}/99-usb-sync.rules "${pkgdir}/etc/udev/rules.d"
+    install -d -m755 $pkgdir/etc/$pkgname
+    install -d -m755 $pkgdir/usr/bin
+    cp ${srcdir}/99-usb-sync.rules "${pkgdir}/etc/udev/rules.d"
+    cp ${srcdir}/${pkgname}.sh "${pkgdir}/usr/bin"
+    cp ${srcdir}/${pkgname}.conf "${pkgdir}/etc/${pkgname}"
 }
diff --git a/udev-usb-sync.conf b/udev-usb-sync.conf
new file mode 100644
index 0000000..31683ee
--- /dev/null
+++ b/udev-usb-sync.conf
@@ -0,0 +1,5 @@
+# default values 
+#use_tweaks=1
+#max_bytes=16777216
+#max_ratio=50
+#strict_limit=1
diff --git a/udev-usb-sync.install b/udev-usb-sync.install
new file mode 100644
index 0000000..7b7452a
--- /dev/null
+++ b/udev-usb-sync.install
@@ -0,0 +1,11 @@
+post_install() {
+	udevadm control --reload
+}
+
+post_upgrade() {
+	post_install
+}
+
+post_remove() {
+	post_install
+}
diff --git a/udev-usb-sync.sh b/udev-usb-sync.sh
new file mode 100755
index 0000000..392a1a1
--- /dev/null
+++ b/udev-usb-sync.sh
@@ -0,0 +1,26 @@
+#!/usr/bin/bash
+#
+# script to tweak USB storage device filesystem sync
+#
+# sources /etc/usb-dev-sync/usb-dev-sync.conf
+#
+
+use_tweaks=1
+max_bytes=16777216
+max_ration=50
+strict_limit=1
+
+# read user config
+source /etc/udev-usb-sync/udev-usb-sync.conf
+
+if [[ "$use_tweaks" = 0 ]]; then
+	exit 0
+fi
+
+if [[ -z "$1" ]]; then
+	exit 1
+fi
+
+echo "$max_bytes" > "/dev/block/$1/bdi/max_bytes"
+echo "$max_ration" > "/dev/block/$1/bdi/max_ratio"
+echo "$strict_limit" > "/dev/block/$1/bdi/strict_limit"