LED Flasher High Visibility

I wanted a high visibility flasher to turn on while I ride from the train station to the office. I simplified citrofan's design by removing a lot of the vertices so it is easier to modify the lid and the box mount points. I also stretched it vertically a bit so you can fit the LEDs mounted int the lid and a 9V battery.

My first attempt at the used a relay circuit, which ate batteries even when I did remember to turn it off. This new version uses 2 transistors and much less power.

Parts List
9V battery and connector
2 x 100 ohm resistors
2 x 100 Kohm resistors
2 x 10 uF capacitors
2 x 2N3906 transistors (or equivalent)
16 x 2x3x4 high brightness LEDs
1 x SPST slider switch
2 x zip ties

The detail for the transistor circuit is here:
https://www.eleccircuit.com/dual-led-flasher-by-2n2907/#Dual_LED_flasher_circuit_using_PNP_transistor
Changing the capacitors and the resistors will allow you to speed up or slow down the alternating LED arrays. Best to experiment on a brea