The Locking D is a decent 'biner at a good price.
Source: bought it new
Price Paid: $6
The Locking D is a decent 'biner at a good price. It does not provide all the [unnecessary] bells and whistles of some other carabiners, but it is going to provide a climber exactly what he needs without breaking the bank.
- Not a lot of versatility
- Narrow gate
I use these every day on my Adventure Challenge course. They are a dependable aluminum carabiner at a low cost. I primarily use them on my climbing gym wall and on my outdoor tower.
I do not use them in my personal gear, because of the cons. The gate is pretty small, making it difficult to clip in with gloved hands. There are lighter 'biners on the market. And I suspect they wouldn't hold up to the abuse I put my 'biners through while caving (To be fair, I haven't put that suspicion to the test.).
If you are looking for a 'biner for the local climbing gym or basic rope work, this is a good one to use. If your needs are a greater (change overs, rope transfers, etc), I'd look elsewhere.