Sailor - Fountain Pen Ink Reservoir - For 50ml Bottle

This small, lightweight plastic insert is custom‑designed to fit Sailor’s square 50 ml ink bottles. When placed inside the bottle, the reservoir gathers ink at a low angle so your pen can reach the final millilitres without tilting the bottle excessively or risking a spill. It’s a simple, cost‑effective tool to minimise ink waste and keep refilling clean and convenient.