This level converter was purchased with the intention to help interface various modules with my Raspberry Pi but here I’m using it with this GPS module (GoodLuckBuy “Skylab GPS Module MT3329 SKM53 with Embedded GPS Antenna Arduino Compatible” SKU: 86236). It uses LVTTL (0 – 3.3V) for its serial RXD and TXD pins. I thought I’d be able to use it without reading the datasheet or tutorials but I struggled with the Output Enable (OE) and with the need for both VCCA and VCCB. In short VCCA needed to go to 5V, VCCB to 3.3V (both on the Arduino) and OE can be left floating / connect to VCCB (I’ve just read there is a 10k pull-up resistor on this pin).
The GPS did work without the level converter so I might steal this part if I need it elsewhere.