Review on Lasenersm 4-Pack 2.53oz /75ml Refillable Roll-On Bottles - Plastic Rollerball Containers for Essential Oils, Perfumes, Balms - Leak-Proof, Reusable, DIY Thin-Waist Style by Dana Lynn

This is exactly what I've been looking for for more than ten years! I use an old rollerball deodorant bottle to apply baby oil after a hot shower. I had to pull out the rollerball to fill it with baby oil. But now they are very easy to fill since the head is unscrewed. Remove ball head with roller, fill, screw head back in. It definitely goes with KISS - keep it simple, stupid! If only they had existed ten years ago. You can use them with anything to top them up, but they make applying baby oil after the shower that much easier - not too much, not too little, just right! I would highly recommend them to anyone!